Answer:
336.1 g of PbS precipitate
Explanation:
The equation of the reaction is given as;
Na2S(aq) + Pb(NO3)2(aq) ----> 2NaNO3(aq) + PbS(s)
Ionically;
Pb^2+(aq) + S^2-(aq) -----> PbS(s)
Number of moles of sodium sulphide= concentration of sodium sulphide × volume of sodium sulphide
Number of moles of sodium sulphide= 0.780 × 1.5 = 1.17 moles
Number of moles of lead II nitrate= concentration of lead II nitrate × volume of lead II nitrate
Number of moles of lead II nitrate= 3.31× 1.00= 3.31 moles
Then we determine the limiting reactant. The limiting reactant yields the least amount of product.
Since 1 moles of sodium sulphide yields 1 mole of lead II sulphide
1.17 moles of sodium sulphide also yields 1.17 moles of lead II sulphide
Hence sodium sulphide is the limiting reactant.
Thus mass of precipitate formed= amount of lead II sulphide × molar mass of sodium sulphide
Molar mass of lead II sulphide= 287.26 g/mol
Mass of lead II sulphide = 1.17 moles × 287.26 g/mol
Mass of lead II sulphide= 336.1 g of PbS precipitate
Consider the equations below.
H₂ → 2H
CHA+HC2H5
C2H5 + HC2H6
When these equations are added together, what will the overall equation be?
C₂H4+H₂C₂H
H2 + CH4 + 2H + C2H5+ → 2H + CH3 + CHE
C2H4 +C2H4 + H2>C2H5 + C2H5
Answer:
a
Explanation:
The overall equation is [tex]C_2H_4 + H_2 ---- > C_2H_6[/tex].
What is Chemical Equation?A chemical equation is defined as a symbolic representation of a chemical reaction in the form of symbols and formulas, in which reactant elements are given on the left and product units on the right.
For example,
[tex]NaOH+ HCl ---- > NaCl+ H_2O[/tex]
In this, reactants are converted to products which is symbolized by a chemical equation. For example, iron (Fe) and sulfur (S) combine to form iron sulfide (FeS).
Fe(s) + S(s) → FeS(s)
here, the plus sign indicates that iron reacts with sulfur.
Thus, the overall equation is [tex]C_2H_4 + H_2 ---- > C_2H_6[/tex].
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1.)A strong acid solution requires 3.2 grams of sulfuric acid (H2SO4). How many molecules of sulfuric acid are in the solution?
2.) While measuring out the sulfuric acid you accidentally spilled some of it! Before trying to clean it up you put some baking soda (NaHCO3) on to it neutralize it. If you scatter 7.8 g of baking soda on the acid how many moles of baking soda have you used?
Answer: 1. There are [tex]0.20\times 10^{23}[/tex] molecules of sulfuric acid in the solution.
2. 0.093 moles of baking soda have been used.
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the moles, we use the equation:
1. [tex]\text{Number of moles of sulpfuric acid}=\frac{\text{Given mass}}{\text {Molar mass}}=\frac{3.2g}{98g/mol}=0.033moles[/tex]
1 mole of [tex]H_2SO_4[/tex] contains = [tex]6.023\times 10^{23}[/tex] molecules of sulfuric acid
Thus mole of [tex]H_2SO_4[/tex] contains = [tex]\frac{6.023\times 10^{23}}{1}\times 0.033=0.20\times 10^{23}[/tex] molecules of sulfuric acid
There are [tex]0.20\times 10^{23}[/tex] molecules of sulfuric acid in the solution.
2. [tex]\text{Number of moles of baking soda}=\frac{\text{Given mass}}{\text {Molar mass}}=\frac{7.8g}{84g/mol}=0.093moles[/tex]
0.093 moles of baking soda have been used.
Which organic compound is saturated?
1.ethene
2.propene
3.ethyne
4.propane
Answer:
3. ethyne
Explanation:
Highest ratio of hydrogen to carbon? I'm not sure I found it on the internet but the answer is right
The correct answer is either a or d. Can anyone explain which one it is and why? CH3C ≡ CCH2CH2Cl is named: a. 1-chloro-3-pentyne b. 5-chloro-2-pentene c. 1-acetylenyl-3-chloropropane d. 5-chloro-2-pentyne
Answer: The IUPAC name of [tex]CH_3C\equiv CCH_2CH_2Cl[/tex] is 5-chloro-2-pentyne
Explanation:
1. First select the longest possible carbon chain. For the number of carbon atom, we add prefix as 'meth' for 1, 'eth' for 2, 'prop' for 3, 'but' for 4, 'pent' for 5, 'hex' for 6, 'sept' for 7, 'oct' for 8, 'nona' for 9 and 'deca' for 10.
2. The longest possible carbon chain should contain all the bonds and functional groups.
3. The numbering is done in such a way that the carbon containing the functional group or substituent gets the lowest number.
4. The naming of alkane is done by adding the suffix -ane, alkene by adding the suffix -ene, alkyne.
Thus the IUPAC name of [tex]CH_3C\equiv CCH_2CH_2Cl[/tex] is 5-chloro-2-pentyne
According to solubility rules, which of the following compounds is soluble in water?
A. Na Coz
B. BaSO4
O C. Ca(NO3)2
D. K3PO4
Answer:
Na2CO3
Explanation:
Na2CO3 is a compound soluble in water. So the correct option is A.
What are solubility rules?
The common ionic solids' solubility laws are as follows. When two rules seem to conflict with one another, the prior rule is used.
Group I element salts (Li+, Na+, K+, Cs+, and Rb+) are soluble. The few exceptions to this rule are rare. Ammonium ion (NH4+) salts are also soluble in water.Nitrate ion (NO3-) salts are often soluble.In general, salts containing Cl, Br, or I are soluble. Ag+, Pb2+, and (Hg2)2+ halide salts are significant exceptions to this norm. PbBr2, Hg2Cl2, and AgCl are hence insoluble.Silver salts are often insoluble. Most silver salts are insoluble, with the exception of AgNO3 and Ag(C2H3O2).Sulfate salts are often soluble. This rule has some notable exceptions, such as CaSO4, BaSO4, PbSO4, Ag2SO4, and SrSO4.The majority of hydroxide salts are hardly soluble. Group I element hydrate salts are soluble. Group II elements (Ca, Sr, and Ba) have soluble hydrate salts. Transition metal and Al3+ hydrate salts are insoluble. Fe(OH), Al(OH), and Co(OH)2 are so insoluble.The majority of transition metal sulfides, such as CdS, FeS, ZnS, and Ag2S, are very insoluble. Sulfides of lead, antimony, bismuth, and arsenic are also insoluble.Many times, carbonates are insoluble. Group II carbonates, including CaCO3, SrCO3, and BaCO3, as well as FeCO3 and PbCO3, are insoluble.Most of the time, chromates are insoluble. PbCrO4 and BaCrO4 are examples.Many phosphates, like Ca3(PO4)2 and Ag3PO4, are insoluble.Many fluorides, including BaF2, MgF2, and PbF2, are insoluble.
Therefore, the correct option is A
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How many grams of chlorine gas are needed to react with 3.5 liters of a 1.7 molar
potassium bromide solution?
Cl2 + 2 KBr - 2 KCl + Br2
Answer: 211.2 grams
Explanation:
To calculate the number of moles for given molarity, we use the equation:
[tex]\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution in L)}}[/tex] .....(1)
Molarity of [tex]KBr[/tex] solution = 1.7 M
Volume of solution = 3.5 L
Putting values in equation 1, we get:
[tex]1.7M=\frac{\text{Moles of}KBr}{3.5L}\\\\\text{Moles of }KBr=\{1.7mol/L\times 3.5L}=5.95moles[/tex]
The balanced chemical reaction is:
[tex]Cl_2+2KBr\rightarrow 2KCl+Br_2[/tex]
According to stoichiometry:
2 mole of KBr requires = 1 mole of [tex]Cl_2[/tex]
5.95 moles of KBr requires = [tex]\frac{1}{2}\times 5.95=2.975[/tex] moles of [tex]Cl_2[/tex]
Mass of [tex]Cl_2=moles\times {\text {Molar mass}}=2.975mol\times 71g/mol=211.2g[/tex]
Thus 211.2 grams of chlorine gas are needed to react with 3.5 liters of a 1.7 molar potassium bromide solution
D
Which word equation shows hydrogen reacting with oxygen to form water?
anygen - water - hydrogen
hydrogen-orbeneater
appudaplu...dk
und---- udaplu
explanation
the chemical formula of water is H²O.
Hydrogen+Oxygen=water
answer
Hydrogen-Water-Hydrogen
The oxide of element X is reduced by heating with carbon.Element X does not react with cold water, steam or dilute hydrochloric acid.What is X?
The question is incomplete, the complete question is;
The oxide of element X is reduced by heating with carbon.
Element X does not react with cold water, steam or dilute hydrochloric acid.
What is X?
A copper
B iron
C magnesium
D zinc
Answer:
Copper
Explanation:
Copper is below hydrogen in the activity series of metals. Remember that the activity series of metals is an arrangement of metals in order of decreasing reactivity from most reactive to least reactive. The metals at the head of the series are highly reactive, metals at the middle of the series are moderately reactive while metals below hydrogen in the series are least reactive.
Copper being below hydrogen in the series cannot displace it from water (cold or steam) or from dilute acid solutions. Copper can be reduced by heating it with carbon (thermal reduction).
What is the definition of acid ?
WILL MARK BRAINLIEST (if the answer is good and hasn't been copied from google and the first one who answer the question )
Answer:
Acid is a compound which dissolves in water to produce hydrogen ions (H+) and described as proton donors.
8. A 65.0 mL 0.513 mol/l solution of glucose (C6H1206) was mixed with 125.0 mL of
2.33 mol/l glucose solution. What is the molar concentration of the final solution?
Assume the volumes are additive. The molar mass of glucose is 180 g/mol (10
points)
Answer:
The molar concentration of the final solution is 1.71 [tex]\frac{moles}{liter}[/tex]
Explanation:
Molarity is a way of expressing the concentration of solutions and indicates the number of moles of solute dissolved per liter of solution.
The molarity of a solution is calculated by dividing the moles of the solute by the volume of the solution.:
[tex]Molarity (M)=\frac{number of moles of solute}{volume}[/tex]
Molarity is expressed in units ([tex]\frac{moles}{liter}[/tex]).
Then, the number of moles of solute can be calculated as:
number of moles of solute= molarity* volume
So, in this case, the final concentration can be calculated as:
[tex]Final molarity (M)=\frac{Total number of moles of solute}{Total volume}[/tex]
where, being 65 mL=0.065 L, 125 mL=0.125 L and 190 mL=0.190 L (because 1000 mL= 1 L):
Total number of moles of solute= 0.065 L*0.513 [tex]\frac{moles}{liter}[/tex] + 0.125 L*2.33 [tex]\frac{moles}{liter}[/tex]= 0.033345 moles + 0.29125 moles= 0.324595 molesTotal volume= 65 mL + 125 mL= 190 mL= 0.190 LReplacing:
[tex]Final molarity (M)=\frac{0.324595 moles}{0.190 L}[/tex]
Final molarity ≅ 1.71 [tex]\frac{moles}{liter}[/tex]
The molar concentration of the final solution is 1.71 [tex]\frac{moles}{liter}[/tex]
1). Calculate the mass of hydrogen peroxide needed to obtain 0.460 L of oxygen gas at STP
2H2O2(aq) → 2H2O(l) + O2(g)
2) 1. Use the reaction shown to calculate the mass of iron that must be used to obtain 0.500 L of hydrogen at STP.
3Fe(s) + 4H2O(l) → Fe3O4(s) + 4H2(g)
Answer:
1) 1.39 grams H2O2
2) 0.933 grams Fe
Explanation:
Step 1: Data given
Volume of oxygen = 0.460 L
STP = 1 atm and 273 K
Step 2: The balanced equation
2H2O2(aq) → 2H2O(l) + O2(g)
Step 3: Calculate the number of moles O2
p*V = n*R*T
⇒with p= the pressure = 1 atm
⇒with V = the volume = 0.460 L
⇒with n = the number of moles = TO BE DETERMINED
⇒with R = the gas constant = 0.08206 L*atm/mol*K
⇒with T = the temperature = 273 K
n = (p*V)/(R*T)
n = (1 * 0.460)/ (0.08206*273)
n = 0.0205 moles moles
Step 4: Calculate moles H2O2
For 2 moles H2O we'll have 2 moles H2O and 1 mol O2
For 0.0205 moles O2 we'll need 2*0.0205 = 0.041 moles H2O2
Step 5: Calculate mass H2O2
Mass H2O2 = moles H2O2 * molar mass H2O2
Mass H2O2 = 0.041 moles * 34.01 g/mol
Mass H2O2 = 1.39 grams
Step 1: Data given
Volume of hydrogen = 0.500 L
STP = 1 atm and 273 K
Step 2: The balanced equation
3Fe(s) + 4H2O(l) → Fe3O4(s) + 4H2(g)
Step 3: Calculate the moles of H2
p**V = n*R*T
⇒with p= the pressure = 1 atm
⇒with V = the volume = 0.500 L
⇒with n = the number of moles = TO BE DETERMINED
⇒with R = the gas constant = 0.08206 L*atm/mol*K
⇒with T = the temperature = 273 K
n = (p*V) / '*T)
n = (1 * 0.500) / (0.08206 * 273)
n = 0.0223 moles
Step 4: Calculate moles Fe
For 3 moles Fe we need 4 moles H2O to produce 1 mol Fe3O4 and 4 moles H2
For 0.0223 moles H2 we'll need 0.0223 *3/4 = 0.0167 moles Fe
Step 5: Calculate mass of Fe
Mass Fe = moles Fe * atomic mass Fe
Mass Fe = 0.0167 moles * 55.845 g/mol
Mass Fe = 0.933 grams Fe
1. The mass of the hydrogen peroxide should be 1.39 grams H2O2.
2) The mass of the iron should be 0.933 grams Fe.
Calculation of the mass:Since
Volume of oxygen = 0.460 L
STP = 1 atm and 273 K
Now The balanced equation
2H2O2(aq) → 2H2O(l) + O2(g)
Now the number of moles O2
p*V = n*R*T
Here p= the pressure = 1 atm
V = the volume = 0.460 L
n = the number of moles = ?
R = the gas constant = 0.08206 L*atm/mol*K
T = the temperature = 273 K
Now
n = (p*V)/(R*T)
n = (1 * 0.460)/ (0.08206*273)
n = 0.0205 moles moles
Now moles H2O2 should be
For 2 moles H2O we'll have 2 moles H2O and 1 mol O2
So,
For 0.0205 moles O2 we'll need 2*0.0205 = 0.041 moles H2O2
Now mass H2O2
Mass H2O2 = moles H2O2 * molar mass H2O2
Mass H2O2 = 0.041 moles * 34.01 g/mol
Mass H2O2 = 1.39 grams
2. The mass of the iron should be
Since
Volume of hydrogen = 0.500 L
STP = 1 atm and 273 K
Now
The balanced equation
3Fe(s) + 4H2O(l) → Fe3O4(s) + 4H2(g)
Now the moles of H2
p**V = n*R*T
Here
p= the pressure = 1 atm
V = the volume = 0.500 L
n = the number of moles = ?
R = the gas constant = 0.08206 L*atm/mol*K
T = the temperature = 273 K
So,
n = (p*V) / '*T)
n = (1 * 0.500) / (0.08206 * 273)
n = 0.0223 moles
Now Calculate moles Fe
For 3 moles Fe we need 4 moles H2O to produce 1 mol Fe3O4 and 4 moles H2
So,
For 0.0223 moles H2 we'll need 0.0223 *3/4 = 0.0167 moles Fe
Now the mass of Fe
Mass Fe = moles Fe * atomic mass Fe
Mass Fe = 0.0167 moles * 55.845 g/mol
Mass Fe = 0.933 grams Fe
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nvironmental Science
a.
Identify the biotic factor of an ecosystem from the following:
soil composition
b. trees
temperature
d. sunlight
C.
Answer:
c
Explanation:
Soil, Plants get energy from the sun.. Answer is C.
Answer:
B. trees
Explanation:
A biotic factor is something in an environment or ecosystem that is living. For example, plants and animals are biotic factors. An abiotic factor is just the opposite-they are not living. Rocks and water are examples of abiotic factors.
Soil composition, temperature and sunlight are all not alive. Therefore, they must be abiotic factors.
Trees are living organism. This means that they are biotic factors. So, the correct answer is B: trees.
What is the mass number of an atom that contains 19 protons, 19 electrons, and 20 neutrons?
Answer:
39
Explanation:
Total protons + total neutrons = mass number
56. What would be the valence electrons of 14Si, 16S, 32Ge respectively?
A. 4, 2,2
B. 4, 6,8
C. 4, 6,6
D. 4,6,4
Answer: D. 4,6,4
Explanation:
The valence electron is the electron found in the outermost shell of an atom, and participates in bond formation.
For the following element, the valence electron can be noticed when we write the electronic configuration of each element.
Silicon = 1s2 2s2 2P6 3s2 3p2
Sulphur = 1s2 2s2 2P6 3s2 3p4
Germanium = 1s2 2s2 2P6 3s2 3p6 3d10 4s2 4p2
rainwater is slightly acidic.why?
Answer:
Rainwater is slightly acidic because...Water reacts with carbon dioxide to form carbonic acid. Due to high carbon dioxide emission in oceans, it explains why sea waters are acidic. Carbonic acid then breaks down into hydrogen ions and hydro carbonates ions. The hydrogen ion raises the water pH and, thus, causes the rainwater to be slightly acidic.
Answer:
Explanation:
rainfall is slightly acidic because of the presence of dissolved carbonic acid. ... The gases of sulfur oxides and nitrogen oxides are chemically converted into sulfuric and nitric acids.
Select True or False: Nitric acid is formed by the gas-phase hydrolysis of N2O5. The energy profile curve for the reaction N2O5 H2O → 2HNO3 is shown here. The reaction is endothermic and the activation energy of the reverse reaction is larger than for the forward reaction.
Answer:
True
Explanation:
Because Nitric acid is formed by the gas-phase hydrolysis of N2O5. The energy profile curve for the reaction N2O5 H2O → 2HNO3 is shown here. The reaction is endothermic and the activation energy of the reverse reaction is larger than for the forward reaction.
In the following reaction, which are the products?
Mg + 2HCl —> H2 + MgCl2
If you could, please explain as well.
Answer: H2 + MgCl2
Explanation: As they are on the right side of the equation/ are the products being made as a result of the reaction, they are the products.
What does the period number tell about the energy levels occupied by electrons in an atom?
Answer:
Number of energy levels that the element has.
Explanation:
The period number (n) is the outer energy level that is occupied by electrons. The period number that an element is in, is the number of energy levels that the element has.
Which list of elements contains a metal, a metalloid,a nonmetal, and a noble gas
Answer:
sodium, silicon, and argon
Explanation:
castle learning
The United States consumes more oil per day than any other country. What would most likely happen to oil prices and availability worldwide if the United States were able to switch immediately to synfuels such as liquefied coal?
A. Oil prices would increase, and availability would increase. B. Oil prices would increase, and availability would decrease.
C. Oil prices would decrease, and availability would increase.
D. Oil prices would remain the same, and availability would increase.
E. Oil prices would remain the same, and availability would remain the same. PLEASE HURRY!!
Answer:
Oil prices would decrease, and availability would increase
Explanation:
If the pH of a solution is 9, the solution is A. acidic, which turns phenolphthalein pink B. acidic, which turns phenolphthalein colorless C. basic, which turns phenolphthalein pink D. basic, which turns phenolphthalein colorless
Answer:
C.
Explanation:
pH > 7, basic, so pH = 9 is basic.
When solution is basic, it will turn phenolphthalein pink.
A piece of lithium metal is added to a beaker that contains water and phenolphthalein. Using what you know about the properties of bases, choose the best explanation for what you observe.
Answer:
The phenolphthalein is turning pink because a base is forming.
What evidence did the team examine that matter is conserved when dry ice changes into a gas?
Answer:
Im not sure what you mean but I hope what I wrote helps you!
The Law of Conservation of Matter says that the amount of matter stays the same, even when matter changes form. Sometimes it may seem that matter disappears during a science experiment, but this law tells us that matter cannot magically appear or disappear, it simply changes from one form to another.
Explanation:
If the pH of a solution is 6.2, what would the pOH be?
O A. 7.8
B. 8.9
C. 12.4
D. 5.8
SUBMIT
Answer:
7.8
Explanation:
pH + pOH = 14
pOH = 14 - 6.2
= 7.8
The sodium salt, NaA, of a weak acid is dissolved in water; no other substance is added. Which of these statements (to a close approximation) is true?
Answer:
Your question is somewhat poorly worded, even so what I can contribute is the statement is false, since the salt is sodium chloride, where its severe chemical formula NaCl, is a SALT not an acid and if it dissolves in water, seriously the solute of a solution, where water plays the role of the solvent
Explanation:
Sodium chloride is a binary salt, very easy to dissolve in water, it is also called the famous table salt, since it can be ingested in food even though it is not so recommended against high blood pressure conditions.
is the study of the natural world through observation and experimentation.
Answer:
YES
Explanation:
The systematic study of the structure and behavior of the physical and natural world through observation and experiment.
what a neat and well labelled diagram of nitrogen cycle in nature
Answer:
In the picture.
I hope it helps
Explanation:
Nitrogen cycle is a complex process (or sequence of reaction) by which nitrogen is removed and added to the soil.
formation of magnesium chloride
-Pure magnesium is commonly made by separating it from seawater. This process is known as electrolysis. The liquid magnesium formed is cooled into convenient blocks of metal known as ingots. The chlorine gas is recycled to form hydrochloric acid for the production of more magnesium chloride.
2. Which change in oxidation number indicates
oxidation?
A) -1 to +2
C) -1 to - 2
B) +3 to +2
D) +2 to -3
Answer:
A)
Explanation:
Increasing of oxidation number shows that the process is oxidation(or losing of electrons).
-1 to +2, oxidation number is increased. This is an oxidation process.
-
What systems need to be in place to ensure fairness in healthcare?
Answer:
The Healthcare system should be a welcome place to the different tiers of people in the society. There should be zero form of discriminations and everyone should be should be treated in the same way. Defaulters should be frowned at and adequate punishments should be meted out. There should be strict accountability of the funds made available to the healthcare centers to prevent diversion and any corrupt practices. These systems need to be in place to ensure fairness in healthcare.
Convert to standard notation.
8.127 x
10-4
Answer:
0.0008127
Explanation:
This is easy