Answer:
0.1 M
<h3>
Explanation:</h3>
- Molarity refers to the concentration of a solution in moles per liter.
- It is calculated by dividing the number of moles of solute by the volume of solvent;
- Molarity = Moles of the solute ÷ Volume of the solvent
<u>In this case, we are given;</u>
- Number of moles of the solute, NH₄Cl as 0.42 moles
- Volume of the solvent, water as 4200 mL or 4.2 L
Therefore;
Molarity = 0.42 moles ÷ 4.2 L
= 0.1 mol/L or 0.1 M
Thus, the molarity of the solution will be 0.1 M
Answer:
<em>293.99 g </em>
OR
<em>0.293 Kg</em>
Explanation:
Given data:
Lattice energy of Potassium nitrate (KNO3) = -163.8 kcal/mol
Heat of hydration of KNO3 = -155.5 kcal/mol
Heat to absorb by KNO3 = 101kJ
To find:
Mass of KNO3 to dissolve in water = ?
Solution:
Heat of solution = Hydration energy - Lattice energy
= -155.5 -(-163.8)
= 8.3 kcal/mol
We already know,
1 kcal/mol = 4.184 kJ/mole
Therefore,
= 4.184 kJ/mol x 8.3 kcal/mol
= 34.73 kJ/mol
Now, 34.73 kJ of heat is absorbed when 1 mole of KNO3 is dissolved in water.
For 101 kJ of heat would be
= 101/34.73
= 2.908 moles of KNO3
Molar mass of KNO3 = 101.1 g/mole
Mass of KNO3 = Molar mass x moles
= 101.1 g/mole x 2.908
= 293.99 g
= 0.293 kg
<em><u>293.99 g potassium nitrate has to dissolve in water to absorb 101 kJ of heat. </u></em>
Answer:
A. Decomposed organic matter
Explanation:
Also water H2O is made of H+ and OH- ions. so when an acidic substance is added to water the concentration of H+ ions increase.
