I know for number 4 the answer is c, sorry I can't help with the others.
If we use mile or something else it will be hard to measure in sky .
Because the mile or meters too short for the space,
Galaxy and stars are too long far away from us if we use mile or meter,
It till be take like miliion year to measure.
Answer:
1.1 mol
Explanation:
n=m/M, where n is moles, m is mass, and M is molar mass.
M of CO2 = 12.01+16.00+16.00 = 44.01g/mol
n=50g/44.01g/mol
n = 1.13610543 mol
n ≈ 1.1 mol
Hope that helps