Answer:
Total pressure = 22.15 atm
Explanation:
Given data:
Total pressure = ?
Volume of container = 7.85 L
Number of moles of N₂ = 4.45 mol
Number of moles of O₂ = 2.45 mol
Temperature = 307 K
Solution:
Pressure of N₂:
PV = nRT
P = nRT/V
P = 4.45 mol ×0.0821 atm.L/mol.K ×307K / 7.85L
P = 112.16 atm.L/7.85 L
P = 14.28 atm
Pressure of O₂:
PV = nRT
P = nRT/V
P = 2.45 mol ×0.0821 atm.L/mol.K ×307K / 7.85L
P = 61.75 atm.L/7.85 L
P = 7.87 atm
Total pressure = P(N₂) + P(O₂)
Total pressure = P( 14.28 atm) + P( 7.87 atm)
Total pressure = 22.15 atm
M(NaCl)=50.0 g
m(H₂O)=150.0 g
m(solution)=m(NaCl)+m(H₂O)
w(NaCl)=100m(NaCl)/m(solution)=100m(NaCl)/{m(NaCl)+m(H₂O)}
w(NaCl)=100*50.0/(50.0+150.0)=25%
Answer:
Explanation:Reaction NaHCO3 + HCl ⇒ NaCl + H2O + CO2
Molar mass M = (22.99+1.008+ 12.01+3·16 ) g/mol. Calculate
Amount of substance n =m/M, n(NaCl) is equal.
M(NaCl) = 58.44 g/mol and mass m= n·M
Answer: 116 calories of energy
Explanation:
A calorie is a non-standard unit of energy.
On combustion,
1 gram Carbohydrates = 4 calories,
1 gram protein = 4 calories,
1gram fat = 9 calories.
Therefore,
15 grams of carbohydrates = (15*4) = 60
5 grams of protein = (5*4) = 20
4 grams of fats = (4*9) = 36
Then add up: 60 + 20 + 36 = 116 calories of energy
Answer : The value of 
of the weak acid is, 4.72
Explanation :
First we have to calculate the moles of KOH.
Now we have to calculate the value of of the weak acid.
The equilibrium chemical reaction is:
Initial moles 0.25 0.03 0
At eqm. (0.25-0.03) 0.03 0.03
= 0.22
Using Henderson Hesselbach equation :
![pH=pK_a+\log \frac{[Salt]}{[Acid]}](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%20%5Cfrac%7B%5BSalt%5D%7D%7B%5BAcid%5D%7D)
![pH=pK_a+\log \frac{[HK]}{[HA]}](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%20%5Cfrac%7B%5BHK%5D%7D%7B%5BHA%5D%7D)
Now put all the given values in this expression, we get:
Therefore, the value of of the weak acid is, 4.72
