Question

A + 2B+ 3C = AB2C3 . Reaction of 6g of A, 61023 atom of B, 0.036 mol of C yields 4.8 g of compound AB2C3. If the atomic mass A and C are 60 and 80 respectively. The atomic mass of B is

Answer 1

Answer:The atomic mass of B is 50 g/mol.

Explanation:

$A+2B+3C+\rightarrow AB_2C_3$

Atomic mass of A = 60 g/mol

Atomic mass of B = x g/mol

Atomic mass of C = 80 g/mol

Moles =$\frac{\text{given mass}}{\text{molar mass}}$

Moles of A = $\frac{6 g}{60 g/mol}=0.1 mol$

Moles of C = 0.036 mol

$6\times 10^{23} atoms$ of B

$1 mol=6.022\times 10^{23}\approx 6\times 10^{23} atoms$

Moles of B = 1 mol

Since , C is present is in least amount and it will act as limiting reagent .

According to 3 mol of C gives 1 mol of $AB_2C_3$, then 0.036 mol of C will give :$\frac{1}{3}\times 0.036$ mol of $AB_2C_3$ that is 0.012 mol.

Moles =$\frac{\text{given mass}}{\text{molar mass}}$

molar mass of $AB_2C_3=60+2x+3(80) g/mol$

$0.012=\frac{4.8 g}{60+2x+3(80)}$

x = 50 g/mol

The atomic mass of B is 50 g/mol.