8.50 moles is equal to 5.1187×10²⁴ atoms of Ca.
<u>Explanation:</u>
We have to multiply the moles of Ca by the Avogadro's number:
= 6.022×10²³
So the number of atoms:
= 8.5 moles × 6.022×10²³atoms / mol
= 5.1187×10²⁴ atoms
Hence the 8.50 moles is equal to 5.1187×10²⁴ atoms of Ca.
Relative formula mass C₅H₁₁ = 71
Now divide the molar mass by the RFM = 142.32 / 71 = 2
Now C₍₅ₓ₂₎H₍₁₁ₓ₂) = C₁₀H₂₂
Hope that helps
<u>Answer:</u> The volume of given amount of ethanol at this temperature is 159.44 mL
<u>Explanation:</u>
Specific gravity is given by the formula:

We are given:
Density of water = 0.997 g/mL
Specific gravity of ethanol = 0.787
Putting values in above equation, we get:

Density is defined as the ratio of mass and volume of a substance.
......(1)
Given values:
Mass of ethanol = 125 g
Density of ethanol = 0.784 g/mL
Putting values in equation 1, we get:

Hence, the volume of given amount of ethanol at this temperature is 159.44 mL