Answer:
0.083 moles KCl
Explanation:
We have 252 mL of 0.33 M KCl. "M" is molarity, and it's measured in mol/L. Since we know the molarity is 0.33 mol/L, in order to find how many moles 252 mL is, we need to multiply our given volume by the molarity.
However, our given volume is in mL, so let's convert to L first by dividing 252 by 1000 (because there are 1000 mL in 1 L):
252/1000 = 0.252 L
Now, we can multiply 0.252 L by 0.33 mol/L to get moles since the L units will cancel out:
0.252 L * 0.33 mol/L = 0.08316
We have two significant figures here, so round 0.08316 to 0.083.
The answer is 0.083 moles.
Hope this helps!
B. When a substance freezes, molecules come close to each other and leads to strong intermolecular bonding.
Answer:
Exothermic reaction.
Explanation:
From the question given, we obtained the following:
The equation for the reaction:
A —> C
From the diagram given in the question above, the reactant, A has a higher energy than the product, C. This simply indicates exothermic reaction as the enthalphy change, ΔH will be negative for the reaction.
Enthalpy change, ΔH is simply the difference between the heat of product, Hp and the heat of reactant, Hr i.e
ΔH = Hp – Hr
Since the heat of the product is small, the enthalphy change, ΔH will be negative indicating that heat has be released to the surroundings. This is termed exothermic reaction.
Answer:
cd
Explanation:
image is formed due to reflected light rays and it is enlarged because image distance/ object distance = height of image/height of object
v>u so image is enlarged
Answer:
Kf = 8.4 x 10²⁶
Explanation:
H₂S(aq) ⇌ HS⁻(aq) + H⁺(aq)
K1 = [HS⁻] [H⁺] / [H₂S]
K1 = 9.76×10−8
9.76×10−8 = [HS⁻] [H⁺] / [H₂S]
HS⁻(aq) ⇌ S²⁻(aq) + H⁺(aq)
K2 = 1.22×10−19
K2 = [S²⁻] [H⁺] / [HS⁻]
S²⁻ (aq) + 2H⁺(aq) ⇌ H₂S(aq)
Kf = [H₂S] /[S²⁻] [H⁺]²
To obtain the value of Kf, the relationship between Kf, k1 and k2 have to be determined;
K1K2 = ( [HS⁻] [H⁺] / [H₂S]) * [S²⁻] [H⁺] / [HS⁻]
K1K2 = [H⁺]² [S²⁻] / [H₂S]
K1K2 = 1 / Kf
Kf = 1 / (K1K2)
Kf = 1 / (9.76×10⁻⁸ * 1.22×10⁻¹⁹)
Kf = 1 / (11.91 x 10-27)
Kf = 0.084 x 10²⁸
Kf = 8.4 x 10²⁶
