Answer : The initial volume was, 71.2 mL
Explanation :
To calculate the volume when temperature and pressure has changed, we use the equation given by combined gas law.
The equation follows:

where,
are the initial pressure, volume and temperature of the gas
are the final pressure, volume and temperature of the gas
We are given:
![P_1=0.85atm\\V_1=?\\T_1=66^oC=[66+273]K=339K\\P_2=0.60atm\\V_2=94mL\\T_2=43^oC=[43+273]K=316K](https://tex.z-dn.net/?f=P_1%3D0.85atm%5C%5CV_1%3D%3F%5C%5CT_1%3D66%5EoC%3D%5B66%2B273%5DK%3D339K%5C%5CP_2%3D0.60atm%5C%5CV_2%3D94mL%5C%5CT_2%3D43%5EoC%3D%5B43%2B273%5DK%3D316K)
Now put all the given values in above equation, we get:


Therefore, the initial volume was, 71.2 mL
Nitrogen has five valence electrons
According to Boyle's Law, P1V1 = P2V2
where P1 and V1 are initial pressure and volume respectively. P2 and V2 are final pressure and volume receptively.
Given: P2 = 4 P1 and V1 = 10.0l
∴ V2 = 2.5 l
Answer: Final volume of system is 2.5 l
M/V=D
65.14/35.4≈1.84
The density of the sulfuric acid would be about 1.84g/mL
Molar mass of sodium=23g
2 mole sodium gives 2 g H2
i.e 46g sodium gives 2g H2
so 65.4g will give=2.84g H2
now no. of molecules = 2.8/2*avogadros number