Find the molar mass of CaCO3 then subtract the molar mass what it originally weighed and the loss of mass. Hopefully this works!
1. D)
2. I think the correct answer from the choices listed above is option C. The tools that <span>should
be used to record the most complete data about a gas are a manometer
and a thermometer. Pressure and temperature are important measurements
for a gas since from these data we can calculate any other properties of
the gas.</span>
D. The particles are tightly packed together
Answer:

Explanation:
Assuming that all caculations are at normal pressure and -1.72°C :

Where
is the number of moles of hydrogen
is the mass of hydrogen
is the density of hydrogen