Question

: For each chemical equation below, write the number of product molecules that will form from the reaction. Then, circle the limiting reactant. (Note: The coefficients in front of the reactants indicate the number of reactant molecules or atoms present.)

A. 5C + 6O2  _______ CO2

B. 4Na + 8Cl2  _______ NaCl

C. 3CO2 + 4H2O  _______ H2CO3
D. 7N2 + 9H2  _______ NH3

E. 10Zn + 16HCl  _______ ZnCl2 + _______ H2

Answer 1

@JustSaiyan

Answer 2

squares are suppose to be arrows pointing right

Answer 3

@Vocaloid

Answer 4

A. 5C + 6O2  _______ CO2

if you only have 5 molecules of C then how many CO2 molecules can you make?

Answer 5

each CO2 molecule needs 1 molecule of carbon

so if you only have 5 molecules of C then how many molecules of CO2 can you make?

Answer 6

i would guess five then

Answer 7

good

for B)
B. 4Na + 8Cl2  _______ NaCl

you have 4 atoms of Na and 8*2 = 16 atoms of Cl

so how many molecules of NaCl can you make if each molecule of NaCl needs 1 Na and 1 Cl atom?

Answer 8

seven?

Answer 9

think of it like making a hot dog - if you have 4 hot dogs + 8 buns, you can only make 4 hot dogs since each hot dog requires 1 hot dog + 1 bun, and you can't make half a hot dog

Answer 10

if NaCl requires 1 Na and 1 Cl, and we only have 4 Na atoms and 8 Cl atoms how many NaCl can we make?

Answer 11

4

Answer 12

good, only 4 NaCl molecules

Answer 13

C. 3CO2 + 4H2O  _______ H2CO3

this one is a little harder; H2CO3 requires 3 oxygen atoms, 2 hydrogen, 1 carbon

on the left side we have:

3 carbons, 8 hydrogens, 10 oxygens

our limiting reactant is carbon - we can only make 3 molecules of H2CO3 since that requires 3 molecules carbon + 6 hydrogen + 9 oxygen, any more than this and we'd run out of carbon

so 3 molecules of H2CO3 for C

Answer 14

D. 7N2 + 9H2  _______ NH3

14 molecules of nitrogen + 18 molecules of hydrogen on the left side

if NH3 requires 1 nitrogen and 3 hydrogens, how many whole NH3 molecules can we make?

Answer 15

8

Answer 16

note: 8 NH3 would require 24 hydrogen atoms and we only have 18 hydrogen atoms

the answer is a little lower than 8

Answer 17

oh?

Answer 18

6?

Answer 19

good, 6

Answer 20

E. 10Zn + 16HCl  _______ ZnCl2 + _______ H2

we are given: 10 Zn atoms, 16 H atoms, 16 Cl atoms

the output requires 1 Zn atom, 2 Cl atoms, 2 H atoms - how many copies of the product can we make with our given atoms?

Answer 21

as a hint:

we have 16 H atoms and the product H2 requires 2 hydrogen atoms - how many molecules of H2 can we make?

Answer 22

8?

Answer 23

for both?

Answer 24

1. What mass of H2O will be produced if 9.5 g of H2 reacts with 1.2 g of O2?
__ H2 + __ O2  __ H2O
2. If 1.85 g of Mg(OH)2 reacts with 3.71 g of HCl, how much MgCl2 is produced? What is the limiting reactant?
__ Mg(OH)2 + __ HCl  __ MgCl2 + __ H2O
3. What mass of potassium hydroxide is formed when 8.2 g of potassium oxide is added to 1.3 g of water? __ K2O + __ H2O  __ KOH
4. What mass of aluminum chloride could be made from 8.1 g of aluminum and 4.2 L of chlorine at STP? __ Al + __ Cl2  __ AlCl3
5. Determine the percent yield for the reaction between 3.74 g of Na and excess O2 if 5.34 g of Na2O2 is recovered.
6. Determine the percent yield for the reaction between 6.92 g of K and 4.28 g of O2 if 7.36 g of K2O is produced.
7. Determine the percent yield for the reaction between 28.1 g of Sb4O6 and excess C if 17.3 g of Sb is recovered along with an unknown amount of CO.
8. Determine the percent yield for the reaction between 45.9 g of NaBr and excess chlorine gas to produce 12.8 g of NaCl and an unknown quantity of bromine gas.