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I am Lyosha [343]
3 years ago
12

How many moles of calcium (Ca) atoms are there in 77.4 g of Ca?

Chemistry
2 answers:
Vinvika [58]3 years ago
8 0
Lar mass of Ca<span> = 40.08 </span>grams/mole 77.4 g Ca<span> * ( 1 </span>mole Ca<span>/ 40.08 ... n = m / M 1mol </span>Ca<span>weights 40 gmol-1 n = 77,4 / 40 = 1.93 </span>mol<span>.</span>
iren [92.7K]3 years ago
3 0

Answer: 1.94 moles

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number 6.023\times 10^{23} of particles.

To calculate the moles, we use the equation:

\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}

Given mass = 77.4 g

Molar mass = 40 g/mol

Putting in the values:

\text{Number of moles}=\frac{77.4g}{40g/mol}=1.94

Thus 1.94 moles of calcium atoms are there in 77.4 g of Ca.

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We know that when P = 0.55 atm, the volume is 5.31 L

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Now, when the gas is at standard pressure ( P = 1 atm)

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