Question

now lets do some stoichiometry with some chemicals other than cookie ingredients. if you wanted to make 36.0 grams of h2o (water) using hydrogen (h2) and oxygen (o2) gas, how many grams of hydrogen (h2) would you need? (answer is in the picture)
stoichiometric calculations
equation: 2 h2(g) + o2(g) —→ 2 h2o(l)
molecules: 2 molecules h2 + 1 molecule o2 —→ 2 molecules h2o
mass (amu): 4.0 amu h2 + 32.0 amu o2 —→ 36.0 amu h2o
amount (mol): 2 mol h2 + 1 mol o2 —→ 2 mol h2o
mass (g): 4.0 g h2 + 32.0 g o2 —→ 36.0 g h2o
the coefficients in the balanced equation give the ratio of moles of reactants and products
○ 4.0 g h2
○ 32.0 g h2
○ 36.0 g h2

Explanation:

Step1: Analyze the stoichiometry table

From the "Mass (g)" row in the table, we see that to produce 36.0 g of \( \text{H}_2\text{O} \), the mass of \( \text{H}_2 \) required is given as 4.0 g (since \( 4.0 \, \text{g H}_2 + 32.0 \, \text{g O}_2
ightarrow 36.0 \, \text{g H}_2\text{O} \)).

Step2: Match with the options

The first option is 4.0 g \( \text{H}_2 \), which matches the value from the stoichiometry table.

Answer:

A. 4.0 g H2