Answer:
The tank with O₂ weighs more.
Explanation:
We can find the mass of gas using the ideal gas equation.

Considering the pressure (P), volume (V), temperature (T) and ideal gas constant (R) are the same, we can establish that:
m ∝ M
The mass is directly proportional to the molar mass. The molar mass of O₂ (32 g/mol) is higher than the molar mass of N₂ (28 g/mol). Therefore, the tank with O₂ weighs more.
Mg3(PO4)2 - the molar mass would be 262g/mol, which is 100%
Atomic mass of Mg is 24, since we have 3Mg we multiply by 3 and get a mass of 72
262 : 100% = 72 : x%
x = 72*100 / 262
x = 27.5%
And do that for every element — get the molar mass of P and multiply by 2, use a ratio, and get the molar mass of O and multiply by 8 and use ratios :)
Answer:
New volume is 14.35 mL
Explanation:
When a system of a gas keeps on constant its temperature and number of moles, the pressure is modified indirectly proportional to the volume:
Pressure increased → Volume decreased
Pressure decreased → Volume increased.
The relation you have to apply is: P₁ . V₁ = P₂. V₂
1.23 atm . 35 mL = 3 atm . V₂
(1.23 atm . 35 mL / 3 atm) = V₂
V₂ = 14.35 mL
An exothermic reaction is a type of reaction that dissipates heat as the reaction proceeds. This would mean that in a closed system, when a reaction proceeds and is endothermic, the temperature of the solution or the system would increase so as to maintain the equilibrium with the whole system.
The answer would be 0.55 moles! good luck!