You need the Avogadro's number. I can't remember exactly the calculation.
Answer:
The mass fraction of ferric oxide in the original sample :
Explanation:
Mass of the mixture = 3.110 g
Mass of 
Mass of 
After heating the mixture it allowed to react with hydrogen gas in which all the ferric oxide reacted to form metallic iron and water vapors where as aluminum oxide did not react.

Mass of mixture left after all the ferric oxide has reacted = 2.387 g
Mass of mixture left after all the ferric oxide has reacted = y

The mass fraction of ferric oxide in the original sample :

If pH is less than seven (pH<7), solution is acidic.
If pH is equal seven (pH = 7), solution is neutral.
If pH is greater than seven (pH > 7), solution is basic.
Some examples:
1) Acidic - gastric juices pH 1, lemon juice pH 2.2, tomato juice pH 4.
2) Neutral - salt solution pH 7.
3) Alkaline - baking soda pH 9, bleach pH 13.
pH is a numeric scale used to specify the acidity or basicity of an aqueous solution.
Answer:
The amount of heat required to raise the temperature of a 32g sample of water from 8°C to 22°C is 1,874.432 J
Explanation:
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
Sensible heat is the amount of heat that a body absorbs or releases without any changes in its physical state (phase change).
Between heat and temperature there is a direct proportional relationship. The constant of proportionality depends on the substance that constitutes the body and its mass, and is the product of the specific heat and the mass of the body. So, the equation that allows to calculate heat exchanges is:
Q = c * m * ΔT
where Q is the heat exchanged by a body of mass m, constituted by a substance of specific heat c and where ΔT is the variation in temperature.
In this case:
- c= 4.184

- m= 32 g
- ΔT= Tfinal - Tinitial= 22°C - 8°C= 14°C
Replacing:
Q= 32 g* 4.184
*14 °C
Solving:
Q= 1,874.432 J
<u><em>The amount of heat required to raise the temperature of a 32g sample of water from 8°C to 22°C is 1,874.432 J</em></u>
Answer:
T₂ = 169.89 K
Explanation:
Given data:
Initial volume = 250 cm³
Initial temperature = 10°C (10+273.15 K = 283.15 K)
Final temperature = ?
Final volume = 150 cm³
Solution:
The given problem will be solve through the Charles Law.
According to this law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.
Mathematical expression:
V₁/T₁ = V₂/T₂
V₁ = Initial volume
T₁ = Initial temperature
V₂ = Final volume
T₂ = Final temperature
Now we will put the values in formula.
V₁/T₁ = V₂/T₂
T₂ = T₁V₂/V₁
T₂ = 283.15 K × 150 cm³ / 250 cm³
T₂ = 42472.5 K. cm³ / 250 cm³
T₂ = 169.89 K