Question

Upon balancing the equation below, how many moles of sodium cyanide are needed to react completely with 3.6 moles of sulfuric acid? H2SO4 + NaCN yields HCN + Na2SO4

Answer 1

You would need 7.2 moles of sodium cyanide to completely react with 3.6 moles of sulfuric acid

Answer 2

Explanation:

The given chemical equation is as follows.

    $H_{2}SO_{4} + NaCN \rightarrow HCN + Na_{2}SO_{4}$

Number of reactant atoms are as follows.

• H = 2
• $SO_{4}$ = 1
• Na = 1
• CN = 1

Number of product atoms are as follows.

• H = 1
• $SO_{4}$ = 1
• Na = 1
• CN = 1

Thus, in order to balance the equation, multiply NaCN by 2 on the reactant side and multiply HCN by 2 on the product side. Therefore, the balanced chemical equation will be as follows.

      $H_{2}SO_{4} +2NaCN \rightarrow 2HCN + Na_{2}SO_{4}$

Hence, we need $2 \times 3.6$  = 7.2 moles of NaCN to react completely with 3.6 moles of $H_{2}SO_{4}$.