Mass of methanol (CH3OH) = 1.922 g
Change in Temperature (t) = 4.20°C
Heat capacity of the bomb plus water = 10.4 KJ/oC
The heat absorbed by the bomb and water is equal to the product of the heat capacity and the temperature change.
Let’s assume that no heat is lost to the surroundings. First, let’s calculate the heat changes in the calorimeter. This is calculated using the formula shown below:
qcal = Ccalt
Where, qcal = heat of reaction
Ccal = heat capacity of calorimeter
t = change in temperature of the sample
Now, let’s calculate qcal:
qcal = (10.4 kJ/°C)(4.20°C)
= 43.68 kJ
Always qsys = qcal + qrxn = 0,
qrxn = -43.68 kJ
The heat change of the reaction is - 43.68 kJ which is the heat released by the combustion of 1.922 g of CH3OH. Therefore, the conversion factor is:
Answer:

Explanation:
1. Molar concentration
Let's call chloroform C and acetone A.
Molar concentration of C = Moles of C/Litres of solution
(a) Moles of C
Assume 0.187 mol of C.
That takes care of that.
(b) Litres of solution
Then we have 0.813 mol of A.
(i) Mass of each component

(ii) Volume of each component

(iii) Volume of solution
If there is no change of volume on mixing.
V = 15.08 mL + 59.70 mL = 74.78 mL
(c) Molar concentration of C

2. Molal concentration of C
Molal concentration = moles of solute/kilograms of solvent
Moles of C = 0.187 mol
Mass of A = 47.22 g = 0.047 22 kg

Answer:
Calcium
Explanation:
Since the element reacts with oxygen to form an oxide with the formula MO, the charge on the element is +2.
Also, since the oxide MO when dissolved in water is basic, the metal is an alkali earth metal.
From the above conditions;
The metal is not arsenic because arsenic is a metalloid has the following oxides As₂O₃ and As₃O₅ and are respectively amphoteric and acidic in nature
The metal is not germanium because is a metalloid and even though germanium oxide has the formula GeO₂, it is amphoteric.
The metal is not chlorine because chlorine is a non-metal
The metal is definitely calcium because calcium oxide has the formula CaO and calcium is an alkaline earth metal.
The metal is not selenium because selenium is anon-meal and its oxide has the formula Se0₂ and is acidic