A gold sample contains 90% of gold and the re | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(B) The mass of the gold sample is $1 \, g$.Since the sample contains $90\%$ gold, the mass of gold present is $0.9 \, g$.The atomic mass of gold $(Au

Vedclass · Accepted Answer

$2.77 	imes 10^{21}$

Vedclass · Answer

(B) The mass of the gold sample is $1 \, g$.Since the sample contains $90\%$ gold, the mass of gold present is $0.9 \, g$.The atomic mass of gold $(Au)$ is approximately $197 \, g/mol$.The number of moles of gold is calculated as: $	ext{moles} = \frac{	ext{mass}}{	ext{atomic mass}} = \frac{0.9 \, g}{197 \, g/mol} \approx 0.004568 \, mol$.The number of atoms is calculated by multiplying the number of moles by Avogadro's number $(N_A = 6.022 	imes 10^{23} \, atoms/mol)$: $	ext{Number of atoms} = 0.004568 	imes 6.022 	imes 10^{23} \approx 2.75 	imes 10^{21} \approx 2.77 	imes 10^{21}$ atoms.

$A$ gold sample contains $90\%$ of gold and the rest copper. How many atoms of gold are present in one gram of this sample of gold?

Similar Questions

Verify by calculating that:
$(a)$ $5 \, mol$ of $CO_2$ and $5 \, mol$ of $H_2O$ do not have the same mass.
$(b)$ $240 \, g$ of calcium and $240 \, g$ of magnesium elements have a mole ratio of $3:5$.

Calculate the number of molecules in $0.5$ mole of water.

State whether the following statement is true or false:
Sodium shows valency of $Na^+$ and $Na^{2+}$.

Give one example each of:
$(a)$ Triatomic element
$(b)$ Monoatomic molecule
$(c)$ Polyatomic element
$(d)$ Polyatomic ion

The visible universe is estimated to contain $10^{22}$ stars. How many moles of stars are present in the visible universe?

Vedclass Test Series

Exam Paper Generator

Online Exam Module