Question

4 HCl + MnO2 ==> MnCl2 + 2 H2O + Cl2

When 1.82 mol of HCl reacts, how many mol of Cl2 form? Use three significant figures in your answer.

Answer 1

We're assuming here that there is excess MnO2 for the HCl to react with (all the HCl is used up in the reaction. You can tell from your balanced reaction that for every 4 molecules of HCl that react, 1 molecule of Cl2 is produced (the ratio is 4:1).

That means if you react 1.82 mol of HCl, you have 4 times FEWER moles of Cl2 produced:

\[{x \over 1.82}={1 \over 4} \rightarrow x = 0.455\]
You can see here that 0.455 mol of Cl2 are produced. Does that make sense?

Answer 2

yes . thats what i got . can u check the rest ?

Answer 3

@matt101

Answer 4

Sure

Answer 5

i sent it to you

Answer 6

Ca + O2 ==> CaO
How many mol of oxygen gas are required to react with 10 mol of calcium? Remember to balance! i got 5


Ag2S + HCl ==> AgCl + H2S
If 35.0 mol of HCl are reacted, how many mol of H2S are produced? Remember to balance. i got 35


Given the chemical equation 2 KClO3 ------> 2 KCl + 3 O2, how many moles of oxygen gas are produced when 3.1 moles of KClO3 react completely? Only enter the numeric value, not the unit.
i got 4.65

SrH2 + 2 H2O ==> Sr(OH)2 + 2 H2
How many mol of water are needed to produce 18.0 mol of strontium hydroxide? i got 36

Hydrogen gas reacts with oxygen gas to produce water. How many mol of hydrogen gas is required to react with 7.28 mol of oxygen gas? Write out your balanced equation, and remember that hydrogen and oxygen are diatomic. i got 3.64


Given the chemical equation 2 KClO3 ------> 2 KCl + 3 O2, how many moles of oxygen gas are produced when 4.0 moles of KClO3react completely?
Show your work to receive credit. Make sure you use proper units when setting up your problem and give your answer using the appropriate number of significant figures.

i said ... 3 mol of O2 / 2 mol of KCIO3 = ? mol of O2 / 4.0 mol of KCIO3 = 6 mol of O2 / 4.0 mol of KCIO3 6 moles of Oxygen gas are produced when 4.0 moles of KCIO3 react completely.

Answer 7

How many mol of oxygen gas are required to react with 10 mol of calcium? 5 is correct!

If 35.0 mol of HCl are reacted, how many mol of H2S are produced? 35 is INCORRECT - remember to balance!

How many moles of oxygen gas are produced when 3.1 moles of KClO3 react completely? 4.65 is correct!

How many mol of water are needed to produce 18.0 mol of strontium hydroxide? 36 is correct!

How many mol of hydrogen gas is required to react with 7.28 mol of oxygen gas? 3.64 is INCORRECT - check your balancing!

How many moles of oxygen gas are produced when 4.0 moles of KClO3 react completely? Your work to find 6 mol is correct!

Answer 8

can you explain the ones that are incorrect .

Answer 9

@matt101

Answer 10

Sure!

First let's write out the balanced equations. What is your balanced equation for those two questions?

Answer 11

Ag2S + HCl ==> AgCl + H2S
the balance equation for this is Ag2S + 2HCI > 2AgCl + H2S
right?

Answer 12

@JessicaAngel u r right......:)

Answer 13

Yup - so now try this question again. Same procedure as what you did in your last question.

Answer 14

35H2S ????

Answer 15

The ratio of HCl to H2S in the equation is 2:1. That means for every mole of HCl that reacts, half a mole of H2S is produced.

\[{x \over 35}={1 \over 2} \rightarrow x=17.5\]
Does that make sense?

Answer 16

A little bit .
so the new ratio would be what ?

Answer 17

35:17.5 right ??

Answer 18

Yes. I'm doing the exact same thing you did in the last question, just using the numbers from THIS question instead.

Answer 19

okay . then it makes sense . i just read it wrong