Answer : The volume of hydrogen gas at STP is 4550 L.
Explanation :
Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.
The combined gas equation is,

where,
= initial pressure of gas = 100.0 atm
= final pressure of gas at STP = 1 atm
= initial volume of gas = 50.0 L
= final volume of gas at STP = ?
= initial temperature of gas = 
= final temperature of gas at STP = 
Now put all the given values in the above equation, we get:


Therefore, the volume of hydrogen gas at STP is 4550 L.
A water solution is found to have a molar oh- concentration of 3.2 x 10-5. the solution would be classified as neutral.
The concentration of hydroxide ions (OH-) is measured by pOH. It is a way of expressing how alkaline a solution is. At 25 degrees Celsius, aqueous solutions with pOH values of 7 or less are neutral, whereas those with pOH values of 7 or more are acidic. The hydrogen ion potential is known as pH. The potential of hydroxide ions is known as pOH. 2. It is a scale used to estimate the hydrogen ion (H+) concentration in the solution. The hydroxide ion (OH-) concentration of the solution is measured using this scale.
pH + pOH = 14
pOH = 3.2x 10-5
[OH-] = 10^(-pOH) =10^(- 3.2x 10-5)
= 0.99
Answer:
6. 7870 kg/m³ (3 s.f.)
7. 33.4 g (3 s.f.)
8. 12600 kg/m³ (3 s.f.)
Explanation:
6. The SI unit for density is kg/m³. Thus convert the mass to Kg and volume to m³ first.
1 kg= 1000g
1m³= 1 ×10⁶ cm³
Mass of iron bar
= 64.2g
= 64.2 ÷1000 kg
= 0.0642 kg
Volume of iron bar
= 8.16 cm³
= 8.16 ÷ 10⁶


Density of iron bar

= 7870 kg/m³ (3 s.f.)
7.

Mass
= 1.16 ×28.8
= 33.408 g
= 33.4 g (3 s.f.)
8. Volume of brick
= 12 cm³

Mass of brick
= 151 g
= 151 ÷ 1000 kg
= 0.151 kg
Density of brick
= mass ÷ volume

(3 s.f.)
The heat required to raise the temperature to a specific temperature change of a sample is related to the specific heat capacity of the substance. In this case, the heat can be calculated through mCpΔT = 350 g * 0.39 J/g C *25 C. This is equal to 3412. 5 Joules. Closest answer is C.