When potassium cyanide reacts with acids a deadly poisonous gas hydrogen cyanide is produced calculate the mass in grams of hydrochloric acid molar mass 36.46 grams per mole needed to completely react with 0.140 grams of potassium cyanide molar mass 65.12 grams per mole to produce hcn
To calculate the mass of hydrochloric acid (HCl) needed to completely react with potassium cyanide (KCN) and produce hydrogen cyanide (HCN), we can use the concept of stoichiometry.
First, we need to write a balanced chemical equation for the reaction:
KCN + HCl -> HCN + KCl
In this reaction, 1 mole of KCN reacts with 1 mole of HCl to produce 1 mole of HCN.
Step 1: Convert the mass of KCN to moles.
Given that the molar mass of KCN is 65.12 grams/mole and the mass of KCN is 0.140 grams, we can calculate the number of moles of KCN as follows:
moles of KCN = mass of KCN / molar mass of KCN
moles of KCN = 0.140 g / 65.12 g/mol
moles of KCN ≈ 0.002146 mol
Step 2: Use the stoichiometry of the balanced chemical equation to determine the moles of HCl required.
From the balanced equation, we see that 1 mole of KCN reacts with 1 mole of HCl to produce 1 mole of HCN. Therefore, the moles of HCl needed will be the same as the moles of KCN:
moles of HCl = moles of KCN ≈ 0.002146 mol
Step 3: Convert moles of HCl to grams.
To determine the mass of HCl needed, we can multiply the number of moles by the molar mass of HCl, which is 36.46 g/mol:
mass of HCl = moles of HCl × molar mass of HCl
mass of HCl = 0.002146 mol × 36.46 g/mol
mass of HCl ≈ 0.0782 g
Therefore, approximately 0.0782 grams of HCl is needed to completely react with 0.140 grams of KCN and produce HCN.