When potassium cyanide (KCN) reacts with acids, a deadly poisonous gas, hydrogen cyaninde (HCN) is given off. Here is the equation: KCN(aq) + HCl(aq) ----> KCl(aq)+ HCN(g)

If a sample of 0.140 g of KCN is treated with an excess of HCl, calculate the amount of HCN formed, in grams.

It appears that the mole ratio is 1:1 from the balanced equation.

How many m oles of KCN is .140 grams?

No indicated moles. :(

In this question, we are asked to find the mass of HCN produced from 0.140 g of KCN. The mass of KCN will be converted to moles of KCN by dividing by its molar mass.

From the balanced chemical equation, we will use the ratio of KCN and HCN to convert moles of KCN consumed into moles of HCN formed. The moles of HCN formed will be converted to grams by multiplying by the molar mass of HCN.

0.140 g KCN * 1 mol KCN / 65.12 g KCN * 1 mol HCN / 1 mol KCN * 27.03 g HCN / 1 mol HCN = ____g HCN

To calculate the amount of HCN formed, you need to apply stoichiometry and use the balanced chemical equation. Here's how you can do it step by step:

Step 1: Determine the molar mass of KCN.
The molar mass of potassium cyanide (KCN) is found by adding the atomic masses of its elements:
K: 39.10 g/mol
C: 12.01 g/mol
N: 14.01 g/mol
Molar mass of KCN = 39.10 + 12.01 + 14.01 = 65.12 g/mol

Step 2: Convert the mass of KCN to moles.
To convert grams to moles, divide the mass of KCN by its molar mass:
0.140 g KCN * (1 mol KCN / 65.12 g KCN) = 0.00215 mol KCN

Step 3: Use the stoichiometry of the balanced equation.
According to the balanced equation, 1 mole of KCN reacts to produce 1 mole of HCN.
Therefore, the molar ratio between KCN and HCN is 1:1.

Step 4: Calculate the amount of HCN formed.
Since the stoichiometry is 1:1 between KCN and HCN, the amount of HCN formed is also 0.00215 mol.

Step 5: Convert moles of HCN to grams.
To convert moles to grams, multiply the amount of HCN (in moles) by its molar mass:
0.00215 mol HCN * (27.03 g HCN/mol) = 0.0581 g HCN

Therefore, the amount of HCN formed when 0.140 g of KCN is reacted with an excess of HCl is approximately 0.0581 grams.

Give me a break. Calculate the moles. You have the mass, you know the formula, calculate the molmass of KCN

moles=mass/molemassKCN