Answer:
-37.63KJ
Explanation:
First, we write an equation of reaction:
H + Br ——-> HBr
Now we are told that 155g of HBr is formed. We can calculate the number of moles of HBr formed as follows:
We simply divide the mass of the HBr formed by the molar mass of HBr. The molar mass of HBr is 81g/mol
The number of moles of HBr formed is thus 81/155 = 0.52 moles
The amount of heat released is thus 0.52 * (-72) = -37.63KJ
Molarity is the most convenient way to express concentration.
Mathematically, molarity is expressed as

In present case,
mass of solute (KCl) = 36 g
molecular weight of KCl = 74.55 g/mol
volume of solution = 100 ml = 0.1 l
∴ Molarity =

= 4.829 M
Thus, conc. of saturated KCl at 20 oC is 4.829 M
Answer:
2.62 atm
Explanation:
1 atm = 14.6959 psi
38.5 / 14.6959 = 2.62 atm
To find the amount of moles in a molecule you divide the grams of the substance by the molar mass.
molar mass of CO2 = 44.01 g
22g / 44.01 = 0.50 moles CO2