I found another question like this. Someone answered "The best answer to this question is adding a catalyst.
Adding a catalyst will cause the greatest increase in the rate of reaction for this chemical reaction , 8Zn(s) + S8(s) 8ZnS(s). ---> adding a catalyst always affects the rate of a reaction."
Answer:
D. 
Explanation:
Hello!
In this case, for the given set of chemical reactions, it is possible to infer that D. is a categorized as redox due to the following:
Since both chlorine and bromine remain as diatomic gases, their oxidation states in such a form is 0, but as anions with lithium cations they have a charge of - according to the following reaction and half-reactions:


Unlike the other reactions whereas no change in the oxidation states is evidenced.
Answer:
The final temperature is 31.95° C.
Explanation:
Given that,
Initial temperature of a sample of chloroform, 
Mass of chloroform, m = 150 g
It absorbs 1 kJ of heat, Q = 10³ J
The specific heat of chloroform, c = 00.96 J/gºC
We need to find the final temperature. The heat absorbed by an object in terms of specific heat is given by :

So, the final temperature is 31.95° C.
Answer:
The balanced chemical equation: NH₃ + 2 HF → NH₄⁺ + HF₂⁻
Explanation:
According to the Brønsted–Lowry acid–base theory, the acid- base reaction is a type of chemical reaction between the acid and base to give a conjugate acid and a conjugate base.
In this reaction, a Brønsted–Lowry acid loses a proton to form a conjugate base. Whereas, a Brønsted–Lowry base accepts a proton to form a conjugate acid.
Acid + Base ⇌ Conjugate Base + Conjugate Acid
The acid dissociation constant (Kₐ) <em>signifies the acidic strength of a chemical species.</em>
∵ pKₐ = - log Kₐ
Thus for a strong acid, Kₐ value is large and pKₐ value is small.
pKₐ (HF) = 3.2 → strong acid
pKₐ (NH₃) = 38 → weak acid
<u>The chemical reaction involved in the dissolution process:</u>
NH₃ + 2 HF → NH₄⁺ + HF₂⁻
In this acid-base reaction, the acid HF reacts with NH₃ base to give the conjugate base HF₂⁻ and conjugate acid NH₄⁺.
<u>HF (acid) donates a proton to form the conjugate base, HF₂⁻ ion. NH₃ (base) accepts a proton to form the conjugate acid. </u>