Answer:
I think it's replacement because the B and D just swap places in the end equation
For every 2 mole Mg we need 1 mole O2 ( based on the equation). since there is 4 mole Mg we need 2 mole O2. one mole O2 is 32 gram so 2 mole would be 64 grams.
Partial pressure can be calculated from balanced equation as :
Partial pressure can be calculated from total pressure and mole fraction of a molecule. The equation of partial pressure is given as:
Mole fraction can be calculated from number of moles of different substances, that we can get from a balanced equation.
If a balanced equation is as follows:
aA+bB---->cP
Mole fraction of A will be =
And partial pressure of A will be:

Answer:
answer is 77.45grams you use stoichimetric formula by comparing CaCl2 and Agcl
A thermometer is used to measure it because the scientific definition of temperature is the average kinetic energy of individual particles in a substance