Answer:
(1) -12 Kcal/mol
Explanation:
Our answer options for this question are:
(1) -12 Kcal/mol
(2) -13 Kcal/mol
(3) -15 Kcal/mol
(4) -16 Kcal/mol
With this in mind, we can start with the chemical reaction (Figure 1). In this reaction, <u>two bonds are broken</u>, a C-H and a Br-Br. Additionally, a C-Br and a H-Br are <u>formed</u>.
If we want to calculate the enthalpy value, we can use the equation:
<u>ΔH=ΔHbonds broken-ΔHbonds formed</u>
If we use the energy values reported, its possible to calculate the energy for each set of bonds:
<u>ΔHbonds broken</u>
<u />
C-H = 94.5 Kcal/mol
Br-Br = 51.5 Kcal/mol
Therefore:
105 Kcal/mol + 53.5 Kcal/mol = 146 Kcal/mol
<u>ΔHbonds formed</u>
C-Br = 70.5 Kcal/mol
H-Br = 87.5 Kcal/mol
Therefore:
70.5 Kcal/mol + 87.5 Kcal/mol = 158 Kcal/mol
<u>ΔH of reaction</u>
<u />
ΔH=ΔHbonds broken-ΔHbonds formed=(146-158) Kcal/mol = -12 Kcal/mol
I hope it helps!
<u />
Answer:
Mg(s) + Sn²⁺(aq) ⇄ Mg²⁺(aq) + Sn(s)
Explanation:
Let's consider the following molecular equation.
Mg(s) + SnSO₄(aq) ⇄ MgSO₄(aq) + Sn(s)
The full ionic equation includes al the ions and the species that do not dissociate in water.
Mg(s) + Sn²⁺(aq) + SO₄²⁻(aq) ⇄ Mg²⁺(aq) + SO₄²⁻(aq) + Sn(s)
The net ionic equation includes only the ions that participate in the reaction (not spectator ions) and the species that do not dissociate in water.
Mg(s) + Sn²⁺(aq) ⇄ Mg²⁺(aq) + Sn(s)
As mentioned above, phosphoric acid has 3 pKa values, and after 3 ionization it gives 3 types of ions at different pKa values:
H₃PO₄(aq)
+ H₂O(l) ⇌ H₃O⁺(aq) + H₂PO₄⁻ (aq) pKₐ₁
<span>
</span>H₂PO₄⁻(aq) + H₂O(l) ⇌ H₃O⁺(aq) + HPO₄²⁻ (aq) pKₐ₂
HPO₄²⁻(aq) + H₂O(l) ⇌ H₃O⁺(aq) + PO₄³⁻ (aq) pKₐ₃
At the highest pKa value (12.4) of phosphoric acid, the last OH group will lose its hydrogen. On the picture I attached, it is shown required protonated form of phosphoric acid before reaction whose pKa value is 12.4.
Answer:
The specific heat capacity of glass is 0.70J/g°C
Explanation:
Heat lost by glass = heat gained by water
Heat lost by glass = mass × specific heat capacity (c) × (final temperature - initial temperature) = 58.5×c×(91.2 - 21.7) = 4065.75c
Heat gained by water = mass × specific heat capacity × (final temperature - initial temperature) = 250×4.2×(21.7 - 19) = 2835
4065.75c = 2835
c = 2835/4065.75 = 0.70J/g°C
<u>Answer:</u> The correct answer is Option B.
<u>Explanation:</u>
Decomposition is a type of chemical reaction in which larger compound breaks down into two or more smaller compounds.

Double displacement reactions is defined as the chemical reaction in which exchange of ions takes place.

Synthesis reaction is a type of reaction in which two or more smaller compounds combines to form a single large compound.

Single displacement reaction is a type of reaction in which a more reactive metal displaces a less reactive metal from its chemical reaction.

In stomach, an acid is present known as hydrochloric acid and to neutralize its effect, antacid is taken which has
as a component.
The reaction between HCl and
is a type of neutralization reaction and it is a type of double displacement reaction.
The equation between the two follows:

Hence, the correct answer is Option B.