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19.4 CHAPTER 19. QUANTITATIVE ASPECTS OF CHEMICAL CHANGE


HCl produced is ( 2 × 0 , 0096 mol), which equals 0 , 0192 mol.

Step 5:Find the mass of hydrochloric acid
m=n×M= 0, 0192 mol× 36 , 46 g·mol= 0, 7 g
(answer to 2)

Exercise 19 - 7


1. Diborane, B 2 H 6 , was once considered for use as a rocket fuel. The com-
bustion reaction for diborane is:
B 2 H 6 (g)+ 3O 2 (g)→ 2 HBO 2 (g)+ 2H 2 O(ℓ)
If we react 2 , 37 g of diborane, how many grams of water would we expect
to produce?
2. Sodium azide is a commonly used compound in airbags. When triggered,
it has the following reaction:
2 NaN 3 (s)→ 2 Na(s)+ 3N 2 (g)
If 23 , 4 g of sodium azide is used, how many moles of nitrogen gas would
we expect to produce? What volume would this nitrogen gas occupy at
STP?
3. Photosynthesis is a chemical reaction that is vital to the existence of life on
Earth. During photosynthesis, plants and bacteria convert carbon dioxide
gas, liquid water, and light into glucose (C 6 H 12 O 6 ) and oxygen gas.
a. Write down the equation for the photosynthesis reaction.
b. Balance the equation.
c. If 3 mol of carbon dioxide are used up in the photosynthesis reaction,
what mass of glucose will be produced?

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(1.) 0085 (2.) 0086 (3.) 0087


358 Chemistry: Chemical change

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