A substance that contains two or more kinds of atoms is
When a balloon is blown up then let go air molecules rush out of the balloon and join the air molecules in earths atmosphere what happens to the enthalpy in the balloon?
Answer: It decreases
Answer: It decreases.
Explanation: a p e x :)
A 90-m3 basement in a residence is found to be contaminated with radon coming from the ground through the floor drains. The concentration of radon in the room is 1.5 Bq/L under steady-state conditions. The room behaves as a CSTR and the decay of radon is a first-order reaction with a decay rate constant of 2.09 3 1026 s21 . If the source of radon is closed off and the room is vented with radon-free air at a rate of 0.14 m3 /s, how long will it take to lower the radon concentration to an acceptable level of 0.15 Bq/L
Answer:
25 minutes
Explanation:
V = Volume = [tex]90\ \text{m}^3[/tex]
[tex]C_0[/tex] = Radon concentration under steady state = 1.5 Bq/L
k = Radon decay rate = [tex]2.09\times 10^{-6}\ \text{s}^{-1}[/tex]
[tex]Q[/tex] = Venting rate = [tex]0.14\ \text{m}^3/\text{s}[/tex]
[tex]C_f[/tex] = Final concentration of radon = 0.15 Bq/L
Theoretical detention time is given by
[tex]\theta=\dfrac{V}{Q}\\\Rightarrow \theta=\dfrac{90}{0.14}\\\Rightarrow \theta=642.86\ \text{s}[/tex]
We have the relation
[tex]C_f=C_0e^{-(\dfrac{1}{\theta}+k)t}\\\Rightarrow t=\dfrac{\ln\dfrac{C_f}{C_0}}{-(\dfrac{1}{\theta}+k)}\\\Rightarrow t=\dfrac{\ln\dfrac{0.15}{1.5}}{-(\dfrac{1}{642.86}+2.09\times 10^{-6})}\\\Rightarrow t=1478.25\ \text{s}=\dfrac{1478.25}{60}=24.63\approx 25\text{minutes}[/tex]
The time taken to reach the acceptable level of concentration is 25 minutes.
Consider a solution which is 0.10M in NH3 and 0.20M in NH4Cl. Choose ALL of the following that are false. If a small amount of NaOH is added, the pH becomes slightly more basic. If HCl is added, the H ions react with the NH3. If a small amount of HCl is added, the pH becomes slightly more basic. If NaOH is added, the OH- ions react with the NH3. If NH4NO3 is added, the pH becomes more basic.
Answer:
The incorrect or the false options are -
(B) - If NH4NO3 is added, the pH becomes more basic.
(D) - If a small amount of HCl is added, the pH becomes slightly more basic.
(E) - If NaOH is added, the OH- ions react with the [tex]NH_3[/tex].
Explanation:
The given solution the buffer basic .
When a small amount of either is added, the hydrogen ion reacts with the ammonium ion, raising the pH slightly.When a small amount of HCl is added, the hydronium ion reacts with the ammonia, raising the pH slightly.Therefore , the options A ( If a small amount of NaOH is added, the pH becomes slightly more basic.) and C ( If HCl is added, the H+ ions react with the NH3.) All other B , D , E are false .
A solution contains 1.817 mg of CoSO4 (155.0 grams/mole) per mL. Calculate the volume (in mL) of 0.009795 M Zn2 needed to titrate the excess complexing reagent after the addition of 70.00 mL of 0.009005 M EDTA to a 20.00 mL aliquot of the Co2 solution.
Answer:
85.952 ml [tex]Zn^2^+[/tex] needed to titrate the excess complexing reagent .
Explanation:
Lets calculate
After addition of 80 ml of EDTA the solution becomes = 20 + 70 = 90 ml
As the number of moles of [tex]CoSO_4[/tex] =[tex]\frac{Given mass }{molar mass}[/tex]
=[tex]\frac{1.817}{155}[/tex]
=0.01172
Molarity = [tex]\frac{no. of moles}{volume of solution}[/tex]
=[tex]\frac{0.01172}{20}[/tex]
=0.000586 moles
Excess of EDTA = concentration of EDTA - concentration of CoSO4
= 0.009005 - 0.000586
= 0.008419 M
As M1V1 ( Excess of EDTA ) = M2V2 [tex](Zn^2^+)[/tex]
[tex]0.008419\times100ml=0.009795\times V2[/tex]
[tex]V2=\frac{0.008419\times100}{0.009795}[/tex]
V2 =85.952 ml
Therefore , 85.952 ml [tex]Zn^2^+[/tex] needed to titrate the excess complexing reagent .
Data Collection
Mass of the original sample of mixture (g) 1.558
Mass of recovered naphthalene (g) 0.483
Mass of recovered 3-nitroaniline (g) 0.499
Mass of recovered benzoic acid (g) 0.467
Calculations:
a. % by mass of naphthalene in original sample.
b. % by mass of 3-nitroaniline in original sample.
c. % by mass of benzoic acid in original sample.
d. total percent recovered.
Answer:
For a): The mass percent of naphthalene in the original sample is 31.00 %.
For b): The mass percent of 3-nitroaniline in the original sample is 32.03 %.
For c): The mass percent of benzoic acid in the original sample is 29.97 %.
For d): The total percent recovered is 93.00 %.
Explanation:
Percentage by mass is defined as the ratio of the mass of a substance to the mass of the solution multiplied by 100. The formula used for this is:
[tex]\text{Percent by mass}=\frac{\text{Mass of substance}}{\text{Mass of a solution}} \times 100[/tex] ......(1)
a):
Mass of naphthalene = 0.483 g
Mass of the sample = 1.558 g
Plugging values in equation 1:
[tex]\%\text{ mass of naphthalene}=\frac{0.483 g}{1.558}\times 100\\\\\%\text{ mass of naphthalene}=31.00 \%[/tex]
b):
Mass of 3-nitroaniline = 0.499 g
Mass of the sample = 1.558 g
Plugging values in equation 1:
[tex]\%\text{ mass of 3-nitroaniline}=\frac{0.499 g}{1.558}\times 100\\\\\%\text{ mass of 3-nitroaniline}=32.03 \%[/tex]
c):
Mass of benzoic acid = 0.467 g
Mass of the sample = 1.558 g
Plugging values in equation 1:
[tex]\%\text{ mass of benzoic acid}=\frac{0.467 g}{1.558}\times 100\\\\\%\text{ mass of benozic acid}=29.97 \%[/tex]
d):
Total mass recovered = [0.483 + 0.499 + 0.467] = 1.449 g
Mass of the sample = 1.558 g
Plugging values in equation 1:
[tex]\text{Total percent recovered}=\frac{1.449 g}{1.558}\times 100\\\\\text{Total percent recovered}=93.00\%[/tex]
N2 + H2 --> NH3 (unbalanced) How many moles of NH3 are produced when 6.3 moles of H2 gas react with N2 gas?
Answer:
4.2 mol NH3
Explanation:
First, balance your reaction.
N2 + 3H2 --> 2NH3
Multiply 6.3 mol H2 by the mole ratio of 2 mol NH3 for every 3 mol H2 to get moles of NH3 produced.
6.3 mol H2 • (2 mol NH3 / 3 mol H2) = 4.2 mol NH3
How many mL of 0.715 M HCl is required to neutralize 1.25 grams of sodium carbonate? (producing carbonic acid)
I really couldn't find the answer since molarity and volume for sodium carbonate are not given.
I will mark the correct answer with steps as best answer.
Answer:
34 mL
Explanation:
We'll begin by calculating the number of mole in 1.25 g of sodium carbonate, Na₂CO₃. This can be obtained as follow:
Mass of Na₂CO₃ = 1.25 g
Molar mass of Na₂CO₃ = (23×2) + 12 + (16×3)
= 46 + 12 + 48
= 106 g/mol
Mole of Na₂CO₃ =?
Mole = mass /molar mass
Mole of Na₂CO₃ = 1.25 / 106
Mole of Na₂CO₃ = 0.012 mole
Next, we shall determine the number of mole HCl needed to react with 0.012 mole of Na₂CO₃.
The equation for the reaction is given below:
Na₂CO₃ + 2HCl —> H₂CO₃ + 2NaCl
From the balanced equation above,
1 mole of Na₂CO₃ reacted with 2 moles of HCl.
Therefore, 0.012 mole of Na₂CO₃ will react with = 0.012 × 2 = 0.024 mole of HCl.
Next, we shall determine the volume of HCl required for the reaction. This is illustrated:
Mole of HCl = 0.024 mole
Molarity of HCl = 0.715 M
Volume of HCl =?
Molarity = mole /Volume
0.715 = 0.024 / volume of HCl
Cross multiply
0.715 × volume of HCl = 0.024
Divide both side by 0.715
Volume of HCl = 0.024 / 0.715
Volume of HCl = 0.034 L
Finally, we shall convert 0.034 L to mL
This can be obtained as follow:
1 L = 1000 mL
Therefore,
0.034 L = 0.034 L × 1000 mL / 1 L
0.034 L = 34 mL
Therefore, 34 mL of HCl is needed for the reaction.
The amount of HCl required for counterbalancing 1.25 g of Na2CO3(Sodium Carbonate) would be:
- [tex]34 ml[/tex]
Given that,
Mass of Na2CO3 [tex]= 1.25 g[/tex]
To find the Moles of Na2CO3, we will find the molar mass of Na2CO3,
Molar Mass of or Na2CO3 [tex]= 106 g/mol[/tex]
So,
Moles of Na2CO3 [tex]= mass /molar mass[/tex]
[tex]= 1.25/106[/tex]
[tex]= 0.012 mol[/tex]
To determine the quantity of HCl required to display the reaction with 0.012 mol of Na2CO3
[tex]Na_{2} CO_{2} + 2HCl[/tex] → [tex]H_{2}CO_{3} + 2NaCl[/tex]
While balancing the equation, we know that [tex]0.012[/tex] × [tex]2 = 0.024 mole of HCl[/tex] is necessary to process the reaction.
Now,
As we know,
HCl moles [tex]= 0.024[/tex]
Molarity of HCl [tex]= 0.715 M[/tex]
∵ Quantity of HCl required = Moles/Molarity
[tex]= 0.024 / 0.715[/tex]
[tex]= 0.034 l[/tex] [tex]or 34ml[/tex]
Thus, 34 ml is the correct answer.
Learn more about 'Molarity' here:
brainly.com/question/12127540
Research and describe one career in health and fitness that you would consider
Answer:
a PE teacher would be in both catagories of heath and fitness
Explanation:
what type of reaction occur in cyclohexene
Cyclohexene is a cyclic, six-membered hydrocarbon that contains one double bond. The types of reactions that can occur in cyclohexene would be those that are typical with alkenes generally.
The pi-bonded electrons in the double bond are nucleophilic. So, electrophilic addition reactions could occur with cyclohexene. For example,
cyclohexene + HBr → bromocyclohexane
cyclohexene + H2O/H+ → cyclohexanol
cyclohexene + Br2 → trans-1,2-dibromocyclohexane (racemic)
The latter is a common test for alkenes where one adds bromine to a sample to see if there is decolorization, which would indicate the presence of nucleophilic pi bonds. Bromine, which is dark reddish-brown, will become clear as it reacts with an alkene to form a colorless haloalkane.
Cyclohexene can also be converted to the fully saturated cyclohexane by hydrogenation: cyclohexene + H2/Pd → cyclohexane.
Good Morning I have a question I need help and can not find the answer o it maybe someone help me? The question is _______ Most Of the Energy that drives water cycle comes from__________? (this is from Science)
Answer:
hydro, water
Explanation:
In what industry do fertilizers and pesticides wash off and contaminate water supplies?Construction Oil Transportation Agriculture
Answer:
The answer is agriculture.
Explanation:
Answer: Agriculture
Explanation:
I got it right on my exam
Please help meeee, I will brainliest. and
Put it into your own words, if u use from internet.
Answer:
energy is used to break bonds in reactants and energy is released when new bonds form in products.The law of conservation of energy states that matter cannot be created or destroyed. Whether a chemical reaction absorbs or releases energy there is no overall change in the amount of energy during the reaction.
Explanation:
Sorry if im wrong
A compound is found to contain 37.32 % phosphorus , 16.88 % nitrogen , and 45.79 % fluorine by
mass.
Question 1: The empirical formula for this compound is :
Question 2: The molar mass for this compound is 82.98 g/mol.
The Molecular formula for this compound is:
Answer: 1. The empirical formula is [tex]PNF_2[/tex]
2. The molecular formula is [tex]PNF_2[/tex]
Explanation:
If percentage are given then we are taking total mass is 100 grams.
So, the mass of each element is equal to the percentage given.
Mass of P = 37.32 g
Mass of N = 16.88 g
Mass of F = 45.79 g
Step 1 : convert given masses into moles.
Moles of P =[tex]\frac{\text{ given mass of P}}{\text{ molar mass of P}}= \frac{37.32g}{31g/mole}=1.20moles[/tex]
Moles of N =[tex]\frac{\text{ given mass of N}}{\text{ molar mass of N}}= \frac{16.88g}{14g/mole}=1.20moles[/tex]
Moles of F =[tex]\frac{\text{ given mass of F}}{\text{ molar mass of F}}= \frac{45.79g}{19g/mole}=2.41moles[/tex]
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For P = [tex]\frac{1.20}{1.20}=1[/tex]
For N = [tex]\frac{1.20}{1.20}=1[/tex]
For F =[tex]\frac{2.41}{1.20}=2[/tex]
The ratio of P: N: F= 1: 1: 2
Hence the empirical formula is [tex]PNF_2[/tex]
The empirical weight of [tex]PNF_2[/tex]= 1(31)+1(14)+2(19)= 82.98 g.
The molecular weight = 82.98 g/mole
Now we have to calculate the molecular formula.
[tex]n=\frac{\text{Molecular weight}}{\text{Equivalent weight}}=\frac{82.98}{82.98}=1[/tex]
The molecular formula will be=[tex]1\times PNF_2=PNF_2[/tex]
Suppose you have a 1:1:1 by weight mixture of three solid compounds, salicylic acid 4-nitroaniline naphthalene. You dissolve 1 gram of this mixture in diethyl ether, and place a tiny drop of the ether solution on a TLC plate. After developing the TLC plate, you see three spots. Which compound would would you expect to have the largest Rf value
Answer:
The correct answer is - 4-nitroaniline.
Explanation:
It is given that all three solid compounds salicylic acid + 4-nitroaniline + naphthalene are equal in the ratio in the mixture and then 1 gram of this mixture is dissolved in the diethyl ether and run a drop of the solution on TLC plate. This plate shows three spots.
The salicylic acid and naphthalene would stay dissolved in the diethyl ether solution due to the 4-nitroaniline could be extracted by adding aqueous acid and involve in the aqueous layer and thus spot of 4-nitroaniline would be with largest Rf value.
how many molecules of sodium chloride are in 2.5 moles??
Answer:
1.5x1024
Explanation:
Which of the following must be overcome by a rocket's thrust?
Answer:
the payloads weight
Explanation:
a p e x on the ground stream
Answer:
The payload's weight
Explanation:
i just took the test on a pex :)
A 1.om sample of dry air at
at 25°c at 786mmHg contains 0.925g Nitrogen Plus other gases including oxygen, argon and carbon dioxide. what is the partial pressure of Na with the air sample.
Answer:
Is the question not supposed to be what is the partial pressure of Nitrogen not Sodium
Atoms of which elements form bonds without satisfying the octet rule?
Answer:
Helium and hydrogen......
What is the mass in grams of 3.40 x 10 24 atoms he
Answer:
Avogadro's constant says that
1
mole of any atom contains
6.022
⋅
10
23
atoms. In this case you have
3.40
⋅
10
22
atoms:
3.40
⋅
10
22
atoms
6.022
⋅
10
23
atoms
mol
=
5.65
⋅
10
−
2
m
o
l
Step 2
The atomic mass of helium (He) will give you the weight of one mole of this molecule:
1
mol =
4.00
gram:
4.00
g
mol
⋅
5.65
⋅
10
−
2
mol
=
0.226
g
So the
3.40
⋅
10
22
helium atoms weigh
0.226
gram
.
Explanation:
Mark as brainlyiest
when 70.0 grams of mno2 reacted with 128.0 grams of hcl, the reaction resulted in a 62.7% yield of chlorine gas. what is the actual yield of chlorine gas in grams? Mno2 + HCI —> MnCl2 + h2o + cl2
Answer:
35.8g of Cl₂ is the yield
Explanation:
Based on the reaction:
MnO₂ + 4HCl → MnCl₂ + 2H₂O + Cl₂
1 mole of MnO₂ and 4 moles of HCl react producing 1 mole of Cl₂
To solve this question we must find limiting reactant. with limiting reactant we can find the theoretical yield of Cl₂. As the actual yield is the 62.7% we can find actual yield of Cl₂ in grams:
Moles MnO₂ -Molar mass: 86.9368g/mol-:
70.0g * (1mol / 86.9368g) = 0.805 moles
Moles HCl -Molar mass: 36.46g/mol-:
128.0g * (1mol / 36.46g) = 3.51 moles
For a complete reaction of 3.51 moles of HCl are required:
3.51 moles HCl * (1mol MnO₂ / 4mol HCl) = 0.878 moles MnO₂.
As there are just 0.805 moles of MnO₂, MnO₂ is limiting reactant.
1 mole of MnO₂ produce 1 mole of Cl₂. The theoretical moles of Cl₂ produced are 0.805 moles.
As the yield is of 62.7%, the yield of Cl₂ is:
0.805 moles * (62.7 / 100) = 0.505 moles Cl₂. In grams:
0.505 moles Cl₂ * (70.906g / mol) =
35.8g of Cl₂ is the yieldWhat mass of nitrogen (N2) is needed to produce 0.125 mol of ammonia (NH3)? Input a numerical answer only. N2 + 3H2 ---> 2NH:
Please help me
How many moles of sodium sulfate are produced along with 5.86 moles of iron(III)
hydroxide?
Fe2(SO4)3 + 6NaOH → 3Na SO4 + 2Fe(OH)3
Answer:
5.86mol 2Fe(OH)3 * [3 mols Na SO4 / 2 mols Fe(OH)3] = 8.79 mols sodium sulfate
Explanation:
To solve this question you need to look at the ratio of sodium sulfate to iron(III) hydroxide. The ratio is 3 to 2, meaning that for every 3 moles of Na SO4 there are also 2 moles of Fe(OH)3. So, you can multiply 5.86 by (3/2) to find the mols of sodium sulfate.
Help me I'm desperate :( no links or u will be reported
Answer:
Here is the answer from somewhere in the internet
Write a formula and balanced equation for the following: solid copper metal reacts with aqueous silver nitrate to produce solid silver metal and aqueous copper Nitrate. How do I know if it will form copper (I) nitrate CuNO3 or copper (II) nitrate Cu(NO3)2 ?
Explanation:
copper (II) nitrate
Illustrate variety of substances of which an element can be part:
metal --> blue solution --> blue solid --> black solid --> blue solution (again) --> metal (again).When solid copper reacts with aqueous silver nitrate, the products are copper (II) nitrate and solid silver. and carbon monoxide gas produces solid iron and carbon dioxide gas.
8. 53.4 mL of a 1.50 M solution of NaCl is on hand, but you need some 0.800 M
solution. How many mL of 0.800 M can you make?
9. A stock solution of 1.00 M NaCl is available. How many milliliters are needed
to make 100.0 mL of 0.750 M
10.2.00 L of 0.800 M NaNO, must be prepared from a solution known to be 1.50
M in concentration. How many mL are required?
PLS answer ASAP!! WILL MARK AS BRAINLYIST!
Nitric oxide (NO) reacts with oxygen gas to produce nitrogen dioxide. A gaseous mixture contains 0.66 g of nitric oxide and 0.58 g of oxygen gas. After the reaction is complete, what mass of nitrogen dioxide is formed? Which reactant is in excess? How do you know? Suppose you actually recovered 0.91 g of nitrogen dioxide. What is your percent yield?
Answer:
NO is the limiting reagent.
In this reaction 0.886 mole of NO2 is produced
Explanation:
The chemical equation for this reaction is
2NO(g) + O2(g) → 2NO2(g)
In this limiting reagent reaction, 2 moles of NO reacts with one mole of O2 to produce 2 mole of 2NO2
0.886 mole of NO * (2 mole of NO2/2 mole of NO) = 0.886 mole of NO2
0.503 mole of O2 * (1 mole of NO2/1 mole of O2) = 1.01 mole of NO2
Hence, NO is the limiting reagent.
In this reaction 0.886 mole of NO2 is produced
A flask contains a 1.00 mole of neon gas and 2.00 moles of argon gas. If the total pressure of the gases is 150.0 kPa, then what is the partial pressure of the argon gas in kPa?
Answer:
Partial pressure of Ar = 100.5 KPa
Explanation:
The following data were obtained from the question:
Number of mole of Ne = 1 mole
Number of mole of Ar = 2 moles
Total pressure = 150.0 KPa
Partial pressure of Ar =?
Next, we shall determine the mole fraction of Argon (Ar). This can be obtained as follow:
Number of mole of Ne = 1 mole
Number of mole of Ar = 2 moles
Total mole = 1 + 2 = 3 moles
Mole fraction of Ar = mole of Ar / total mole
Mole fraction of Ar = 2/3
Mole fraction of Ar = 0.67 mole
Finally, we shall determine the partial pressure of argon (Ar). This can be obtained as follow:
Mole fraction of Ar = 0.67 mole
Total pressure = 150.0 KPa
Partial pressure of Ar =?
Partial pressure = mole fraction of gas × total pressure
Partial pressure of Ar = 0.67 × 150
Partial pressure of Ar = 100.5 KPa
Calculate the percent composition of C in carbon dioxide.
Answer:
27.27%
Explanation:
6. (5 pts) From among the isomeric compounds with molecular formula C4H9Cl, identify the one having a 1H NMR spectrum that: a) contains only a single peak b) has several peaks, including a doublet at d 3.4 c) has several peaks, including a triplet at d 3.5 d) Has several peaks, including two distinct signals, each with an integration of 3H, one of them a triplet at d 1.0 and the other a doublet at d 1.5.
Answer:
Explanation:
Chemically identical protons in 1HNMR spectra are protons that are found in the same chemical system and produce one signal in the spectra. Non-equivalent protons are protons that reside in various chemical environments and display different signals.
(a) The provided alkyl halide has four carbons, nine hydrogens, and one chlorine atom, according to the molecular formula. To achieve a single NMR peak, all protons (9 hydrogens) must be in the same chemical environment. That is, the carbon skeleton should be made up of three methyl groups, each bound to a single carbon atom.
As a consequence, the tert-butyl chloride structure can be present. That it has three methyl groups that are all the same and are all bound to the same carbon atom. As a result. A single peak is generated by proton NMR.
(b) The other isomeric variant of C4H9Cl, which has several peaks and a doublet at d3.4, could have a proton at a nearby carbon. And then does it produce a doublet. To create the doublet, two methyl groups should be substituted for the carbon. The value of 3.4 indicates that the protons can be exposed to chlorine. As a result, the compound's composition is iso-butyl chloride.
(c) The compound C4H9Cl can have two protons on adjacent carbons since it has multiple peaks and a triplet at d3,5. And then does it generate a triplet. The meaning of 3.5 indicates that the protons should be exposed to chlorine. As a result, the compound's composition is n-butyl chloride.
(d) The compound C4H9Cl has many peaks, including a methyl group triplet at d1.0 and a methyl group doublet after. It's in the same family as the -CH party. Due to the chlorine atom, this doublet occurs at downfield at 1.5. As a result, the compound's composition is sec-butyl chloride.