It should remain constant because of the law of conservation of mass and because the flask is sealed no mass will escape
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
Answer:
moles Ar in 20g = 0.500 mole Ar
Explanation:
moles = grams given / formula weight = 20g / 39.948g·mol⁻¹ = 0.500 mole Ar
Answer:
Answer of question a is 345J.
Explanation:
In question a following is given in data:
-mass of iron (m) = 10.0 g
-temperature (ΔT) = final temperature- initial temperature= 100-25= 75 degree Celsius
-Specific Heat capacity of iron (c)= 0.46J/g°C.
Heat (Q)=?
Solution:
Formula for Heat is :
Q=m x c x ΔT
Q= 10 x 0.46 x 75
Q= 345 J.
so, 345 joules of heat is needed to increase the temperature of 10 grams of iron.
- From the above formula all other questions can easily be solved from the same procedure.