Answer:
1.57 × 10^-4
one point five seven times ten to the power of negative four
A 8.15 g sample of hydrogen peroxide (H2O2) decomposes to form water and oxygen. The temperature and pressures conditions in the lab were 21.2oC and 761.4 torr, respectively. The oxygen gas is collected over a sample of water at 21.2oC; the vapor pressure of water at that temperature is 18.9 torr. When the water level inside and outside of the tube is equal the volume of gas is recorded as 176.23 mL. a) Write and balance the equation for the decomposition reaction
Answer: [tex]H_2O_2\rightarrow H_2+O_2[/tex]
Explanation:
Decomposition is a type of chemical reaction in which one reactant gives two or more than two products.
According to law of conservation of mass, mass can neither be created nor be destroyed. Thus the number of atoms of each element must be same on reactant and product side. Thus chemical equations are balanced.
The balanced equation for the decomposition reaction of hydrogen peroxide is:
[tex]H_2O_2\rightarrow H_2+O_2[/tex]
Decomposition is a type of chemical reaction in which a chemical breaks into two or more molecules or atoms. One reactant breaks into two products which can be shown as:
XY----->X + Y
The decomposition reaction of hydrogen peroxide can be written as:
[tex]H_{2}O_{2} = H_{2} + O_{2}[/tex]
According to the mass conserving law the mass can neither be added nor deleted they can just get transferred. For a reaction to be stable the number of atoms on both sides of the reaction should be balanced.Therefore, the balanced chemical reaction of decomposition of hydrogen peroxide will be:
[tex]H_{2}O_{2} = H_{2} + O_{2}[/tex]
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In a laboratory experiment, students synthesized a new compound and found that when grams of the compound were dissolved to make mL of a diethyl ether solution, the osmotic pressure generated was atm at K. The compound was also found to be nonvolatile and a non-electrolyte. What is the molar mass they determined for this compound
The question is incomplete, the complete question is;
In a laboratory experiment, students synthesized a new compound and found that when 12.23 grams of the compound were dissolved to make 228.1 mL of a benzene solution, the osmotic pressure generated was 4.55 atm at 298 K. The compound was also found to be non-volatile and a non-electrolyte. What is the molecular weight they determined for this compound?
Answer:
287.76 g/mol
Explanation:
From;
π = M R T
M = molarity
R= gas constant
T = temperature
number of moles = π * volume/RT
number of moles = 4.55 * 228.1/1000/0.082 * 298
number of moles = 1.037855/24.436
number of moles = 0.0425 moles
Molar mass = mass/number of moles
Molar mass = 12.23 grams/0.0425 moles
Molar mass = 287.76 g/mol
What is the volume in mL of 0.36 mol of carbon dioxide at STP?
Answer:
Zero
Explanation:
How many carbon atoms are represented by Mg(HCO3)
1. Why does light bend when it changes medium?
Answer:
The bending of light as it passes from one medium to another is called refraction
Explanation:
ANSWER ASAP
2. The figure shows the first three rows, or periods, of the periodic table. Suppose the fourth period is added. How many orbits will the Bohr models in the fourth period have? How many electrons will an atom in Group 1 in the fourth period have?
Answer:
4 orbits in the fourth period.
19 electrons in the atom from group 1 and fourth period.
Explanation:
Potassium has 19 electrons distributed in its 4 orbits
The number of periods in a periodic table, tells the number of shells or orbitals of the atoms in that row in which the electrons are filled. Thus the fourth period elements have 4 orbitals and the first element in group one of the fourth period is potassium containing 19 electrons.
What are periods in periodic table?All elements in a periodic table are classified into different groups and periods. The vertical columns in the periodic table is called groups and the horizontal rows are called periods.
A group contains elements with same number of valence electrons and similar physical and chemical properties. In a period from left to right the atomic number increases but the number of orbitals in which the electrons are filled will be the same.
Down a group the number of orbitals increases by one. Thus, each elements contains electrons in an increment of 8, 18, 18 and 32 down a group. Thus, from third period to fourth period the number of orbital increases to 4.
The number of electrons will be +8 from the previous element in the group in third period. Thus, below sodium (11) the first element in fourth period is potassium with 19 electrons.
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Alright
Ooh, yeah
I'll admit, I was wrong, what else can I say, girl?
Can't you blame my head and not my heart?
I was drunk, I was gone, that don't make it right, but
I promise there were no feelings involved, mmh
She said, "Boy, tell me honestly
Was it real or just for show?", yeah
She said, "Save your apologies
Baby, I just gotta know"
How long has this been goin' on?
You been creepin' 'round on me
While you're callin' me "baby"
How long has this been goin' on?
You've been actin' so shady (shady)
I've been feelin' it lately, baby
Ooo-oh (yeah)
Ooo-oh (encore)
Oooh-ooh-oh
NEVER GONNA GIVE YOU UP,
NEVER GONNA LET YOU DOWN,
NEVER GONNA RUN AROUND AND DESERT YOU!
NEVER GONNA MAKE YOU CRY,
NEVER GONNA SAY GOODBYE..
Answer:
How long By Charlie Puth
metric conversion ( convert )
Answer:
13. 2g
14. 5000mL
15. 104,000m
16. 160mm
17. 5600000mg
18. 10hs
19. 0.250km
20. 1daL
Explanation:
13. 1000milligram (mg) = 1gram (g)
Hence, 2000mg = 2000/1000
= 2g
14. 1 litre (L) = 1000millilitre (mL)
Hence, 5L = 5 × 1000
= 5000mL.
15. 1kilometre (km) = 1000metre (m)
Hence, 104km = 104 × 1000
= 104,000m
16. 1 centimetre (cm) = 10millimeters (mm)
Hence, 16cm = 16 × 10
= 160mm
17. 1kilogram (kg) = 1000000 milligram (mg)
Hence, 5.6kg = 5.6 × 1000000
= 5600000mg
18. 1 second (s) = 0.01 hectosecond (hs)
Hence, 1000s = 1000 × 0.01
= 10hs
19. 1000metre (m) = 1kilometre (km)
Hence, 250m = 250/1000
= 0.250km
20. 1 centiliter (cl) = 0.001 Decaliter (daL)
Hence, 1000cl = 1000 × 0.001
= 1daL
Which example is a long-term environmental change?
O La Niña
O EI Nino
O climate change
O small asteroid impact
C
The graph below shows a reaction to which a catalyst has been added. How would the graph be different if it showed the same reaction without a catalyst?
A. The width of region 2 would be smaller.
B. The difference in the heights of regions 1 and 3 would be larger.
C. The height of region 2 would be larger
D. The distance between regions 1 and 3 would be smaller
Answer:
a. the width of region 2 would be smaller
If the same reaction was shown without a catalyst, the height of region 2 would be larger, so the correct option is (C).
What is catalyst?A catalyst is a substance that speeds up the rate of a chemical reaction without being consumed in the process. It works by providing an alternate pathway for the reaction with a lower activation energy, making it easier for the reactants to transform into products.
Catalysts can be solids, liquids, or gases, and they can be homogeneous or heterogeneous, depending on whether they are in the same phase as the reactants or in a different phase.
Catalysts are widely used in many industrial processes, such as the production of fertilizers, plastics, and fuels, to increase the efficiency and reduce the cost of the reaction. They can also be found in biological systems, where they play a crucial role in metabolic processes, such as the breakdown of food in the digestive system or the conversion of light into chemical energy in photosynthesis.
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An extraction procedure specifies that an aqueous solution containing dissolved organic material be extracted twice with 10 mL portions of diethyl ether. A student removes the lower layer after the first extraction and adds the second 10 mL portion of ether to the remaining upper layer. After shaking the separatory funnel, the student observes only one liquid phase with no interface. Explain.
Answer: The student observed only one liquid phase because The student removed the aqueous layer instead of the organic layer and then added organic solvent to more organic layer. Diethyl ether is less dense than water.
Explanation:
In organic chemistry, which is the chemistry of carbon atoms, liquid-liquid extraction techniques are used to separate solutes from its crude reaction mixtures. An example of liquid- liquid extraction technique used is the Separatory funnel.
The Separatory funnel extraction technique allows the separation of solutes based on their solubilities in two immiscible liquids. This appears as two phases or layers with the organic solvent on top while the aqueous solution is below the funnel. This is because the organic solvents are less dense than the aqueous solution.
From the question, the student had a dissolved organic compound in an aqueous solution and was given an organic solvent, diethyl ether for its extraction. When the first 10ml of ether was added, the dissolved organic compound mixed with it and remained in the top layer of the mixture. The student removes the lower layer after the first extraction and adds the second 10mL portion of ether to the upper layer remaining in the separatory funnel. After shaking the funnel, the student observes only one liquid phase with no interface because more organic solvent was added to the organic layer that remained after the aqueous layer was removed.
How many atoms are in 4 moles of oxygen?
Using Avogrado's constant (6.022e23):
4(6.022e23) = 2.41e24
If a substance has a density of 2.545g / mL how many grams would the substance weigh if the sample has a volume of 122.1 mL?
Answer: 310.7 grams
Explanation:
Multiply the two values so the units of mL cancel and you get grams
2.545*122.1 = 310.7 grams
Which type of lens would you use in a microscope or telescope and why?
Answer:
Microscopes and telescopes often use two lenses to make an image large enough to see. A compound microscope uses two lenses to achieve high magnification. Both lenses are convex, or converging. Light from the object first passes through the objective lens.
Explanation:
A compound microscope uses two lenses to achieve high magnification
what is the difference between fluorine and oxygen?
Answer:
Continuing on across the periodic table we see that fluorine is the next element after oxygen. ... Rather than forming seven bonds fluorine only forms a single bond for basically the same reasons that oxygen only forms two bonds. Hydrogen fluoride, HF, has one bond, but four centers of electron density around the fluorine.
Calculate the number of moles 2.5 g of calcium hydroxide.
0.044 mol CaOH
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableWriting CompoundsStoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
2.5 g CaOH
Step 2: Identify Conversions
[PT] Molar Mass of Ca - 40.08 g/mol
[PT] Molar Mass of O - 16.00 g/mol
[PT] Molar Mass of H - 1.01 g/mol
Molar Mass of CaOH - 40.08 + 16.00 + 1.01 = 57.09 g/mol
Step 3: Convert
[DA] Set up: [tex]\displaystyle 2.5 \ g \ CaOH(\frac{1 \ mol \ CaOH}{57.09 \ g \ CaOH})[/tex][DA] Multiply/Divide [Cancel out units]: [tex]\displaystyle 0.043791 \ mol \ CaOH[/tex]Step 4: Check
Follow sig fig rules and round. We are given 2 sig figs.
0.043791 mol CaOH ≈ 0.044 mol CaOH
How many nitrogen
atoms (N) are in 2N2
Answer: it's 4nitrogen
denotes two nitrogen atoms. 2. N 2 denotes one molecule of nitrogen gas.
Explanation:
The work of which scientist was most essential to the use of radioactive
isotopes in medicine?
A. Antoine-Laurent Lavoisier
B. Robert Boyle
C. Marie Curie
D. John Dalton
Answer:
A
Antoine-Laurent Lavoisier
:D
The scientist was most essential to the use of radioactive isotopes in medicine is " John Lawrence's".
What is radioactive isotopes?The radioactive isotopes of such an element were called radioisotopes. Atoms that have too much energy in their nucleus or even an unstable neutron-proton pair.
It marked the beginning of John Lawrence's lengthy career of service and the first time a radioactive isotope had already been employed in the management of a human illness. His laboratory is regarded as the origin of nuclear medicine, for which he is regarded as its father.
The scientist most essential to the use of radioactive isotopes in medicine is " John Lawrence's".
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What makes an atom a good conductor?
A solid sample of Zinc Hydroxide is added to 0.350 L of 0.500 M aqueous Hydrogen Bromide. The solution that remains is still acidic. It is then titrated with 0.500 M NaOH solution, and it takes 88.5 mL of the NaOH solution to reach the equivalence point. What mass of Zinc Hydroxide was added to the Hydrogen Bromide solution?
Answer:
6.499 g
Explanation:
One part of the aqueous HBr reacted with Zinc Hydroxide following the reaction:
Zn(OH)₂ + 2HBr → ZnBr₂ + 2H₂OAnd the remaining HBr reacted with NaOH:
NaOH + HBr → NaBr + H₂OFirst we calculate how many HBr moles remained after reacting with Zn(OH)₂. That number equals the number of NaOH moles used in the titration:
0.500 M * 88.5 mL = 44.25 mmol NaOH = mmol HBrNow we calculate how many moles of HBr reacted with Zn(OH)₂:
Originally there were (350 mL * 0.500 M) 175 mmol HBr175 mmol - 44.25 mmol = 130.75 mmol HBrThen we convert those 130.75 mmoles of HBr to the Zn(OH)₂ moles they reacted with:
130.75 mmol HBr * [tex]\frac{1mmolZn(OH)_{2}}{2mmolHBr}[/tex] = 65.375 mmol Zn(OH)₂.Finally we convert Zn(OH)₂ moles to grams:
65.375 mmol Zn(OH)₂ * 99.424 mg/mmol = 6499.8 mg Zn(OH)₂6499.8 mg Zn(OH)₂ / 1000 = 6.499 gWhich equation illustrates conservation of mass?
O 1 H2 + 1 O2 + 2 H2O
O 1 H2 + 1 2 + 1 H2O
O 1 H2 + 1 Cl2 +1HCI
O 1 H2 + 1 Cl2 + 2HCI
Answer:
1H₂ + 1Cl₂ → 2HCl
Explanation:
The reaction that illustrates the law of conservation of mass is shown below:
1H₂ + 1Cl₂ → 2HCl
According to the law of conservation of mass "in a chemical reaction, matter is neither created nor destroy but atoms are rearranged".
Therefore, we are expected to the end a reaction with the amount of substance we start with.
Element H Cl
Reactants 2 2
Products 2 2
We see that number of atoms on both sides are the same.
WORTH 18 POINTS! MY LIFE DEPENDS ON THIS ANSWER!!!
Which compound listed below is most likely to have to following properties?
-solid at room temperature
- high melting points
-solble in water
-conductive when dissolved
1.sodium chloride
2.carbon monoxide
3.nitrogen trifluoride
4.none of these compounds could have all of the properties listed
Answer:
1.sodium chloride
Explanation:
because the others dont have all the listed properties
There diagrams imply that’s
A TISSUEs are always rectangular
B tissues are made up of cells
C Tissues all look the same
D tissues have the same Function
Answer:
b
Explanation:
bsbsbsbbebensnnsjswjjejejejejek
Characteristics of a substance that can be measured or observed by changing the identity of the material is a
Group of answer choices
A. physical property
B. chemical property
C. physical change
D. chemical change
Fresh milk has a pH of 6.
How do you think the pH
would change as it became
sour? Explain your answer.
a certain kind of pea plant has an allele for tall and an allele for short but its overall phenotype is tall.
Answer:
Tt
Explanation:
T= Dominant tall
t= non-dominant short.
Dominant always shows over non-dominant.
Question 7 (1 point)
Order the levels of organization from smallest to largest.
11. Organism
1 2. Cell
13. Organ System
1 4. Organ
1 5. Tissue
I need some help to determine the mole and grams pls I would really appreciate the help
Answer:
[tex]n_{FeS}=0.686molFeS \\\\n_{H_2S}=23.3gH_2S[/tex]
Explanation:
Hello!
In this case, according to the given chemical reaction, it is possible to apply the following stoichiometric setups in order to compute the moles of reacting FeS and the grams of produced H2S, given the mass of HCl (molar mass = 36.46 g/mol) as shown below:
[tex]n_{FeS}=50.0gHCl*\frac{1molHCl}{36.46gHCl}*\frac{1molFeS}{2molHCl}\\\\n_{FeS}=0.686molFeS \\\\\\m_{H_2S}=50.0gHCl*\frac{1molHCl}{36.46gHCl}*\frac{1molH_2S}{2molHCl}*\frac{34.04gH_2S}{1molH_2S} \\\\n_{H_2S}=23.3gH_2S[/tex]
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Helppp plssss pls help it’s Science I will give Brainlyist no cap I will just plssss help
Answer:
I cant see it that well but id be happy to help if u post a clearer picture!
Explanation:
14. Which of the following statements about phase changes are TRUE?
Answer:
Hate to take up this answer spot, but there is no statements about phase changes.
Here are some phase changes to help: when matter changes phase. Most common ex. is water(liquid) to ice(solid). It is created by particles coming together, or spreading apart.
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