Five hundred twenty million, three hundred and forty thousand. hope it helps!
the answer is c, more heat is being released.
Answer:
70.77 g/mol is the molar mass of the unknown gas.
Explanation:
Effusion is defined as rate of change of volume with respect to time.
Rate of Effusion=
Effusion rate of oxygen gas after time t = 
Molar mass of oxygen gas = M = 32 g/mol
Effusion rate of unknown gas after time t = 
Molar mass of unknown gas = M'
The rate of diffusion of gas, we use Graham's Law.
This law states that the rate of effusion or diffusion of gas is inversely proportional to the square root of the molar mass of the gas. The equation given by this law follows:



M' = 70.77 g/mol
70.77 g/mol is the molar mass of the unknown gas.
The reaction is a displacement reaction. Iron is more reactive than copper. Hence, it displaces copper,forming iron II sulfate and copper metal.
This reaction is an exothermic reaction, hence it releases energy. The colour change indicates that iron has displaced copper.