<h3>1.<u> Answer;</u></h3>
False
<h3><u>Explanation;</u></h3>
Bases have some of the following properties;
- They have a bitter taste
- They have a slimy, or soapy feel on fingers
- Most bases react with acids and precipitate salts.
- Strong bases may react violently with acids.
- Bases turn red litmus paper blue
<h3>2. <u>Answer;</u></h3>
An acid
<h3><u>Explanation;</u></h3>
- When acids are dissolved in water, the concentration of the acid decreases and it becomes dilute.
- It dissociates in water to give H+ ions or hydrogen ions.
- All acidic solutions contain more hydrogen ions than hydroxide ions, therefore when added to water it increases the concentration of H+ ions in water, as water is a neutral substance whose concentration of H+ ions is equal to OH-.
The answer is 67 108.0888km/s.
The mass per volume of a substance is called its density.
Answer:
(D) Na₂SO₄•10H₂O (M = 286).
Explanation:
- The depression in freezing point of water by adding a solute is determined using the relation:
<em>ΔTf = i.Kf.m,</em>
Where, ΔTf is the depression in freezing point of water.
i is van't Hoff factor.
Kf is the molal depression constant.
m is the molality of the solute.
- Since, Kf and m is constant for all the mentioned salts. So, the depression in freezing point depends strongly on the van't Hoff factor (i).
- van't Hoff factor is the ratio between the actual concentration of particles produced when the substance is dissolved and the concentration of a substance as calculated from its mass.
(A) CuSO₄•5H₂O:
CuSO₄ is dissociated to Cu⁺² and SO₄²⁻.
So, i = dissociated ions/no. of particles = 2/1 = 2.
B) NiSO₄•6H₂O:
NiSO₄ is dissociated to Ni⁺² and SO₄²⁻.
So, i = dissociated ions/no. of particles = 2/1 = 2.
(C) MgSO₄•7H₂O:
MgSO₄ is dissociated to Mg⁺² and SO₄²⁻.
So, i = dissociated ions/no. of particles = 2/1 = 2.
(D) Na₂SO₄•10H₂O:
Na₂SO₄ is dissociated to 2 Na⁺ and SO₄²⁻.
So, i = dissociated ions/no. of particles = 3/1 = 3.
∴ The salt with the high (i) value is Na₂SO₄•10H₂O.
So, the highest ΔTf resulted by adding Na₂SO₄•10H₂O salt.
