Answer:
2.1 x 10⁻².
Explanation:
- Generally, the equilibrium constant (Keq) is the product of the concentration of the reaction products divided by the product of the concentration of the reaction reactants, each term is raised to a power equal to its coefficient in the balanced chemical reaction.
- For the given reaction: 2HF → H₂ + F₂,
Keq = [H₂][F₂] / [HF]²,
Keq = [H₂][F₂] / [HF]² = [8.4 x 10⁻³][8.4 x 10⁻³] / [5.82 x 10⁻²]² = 2.1 x 10⁻².
Answer:
oK so pay pattention to the fractions
Explanation:
A bike rusting is an example of a chemical
change since rusting is a chemical reaction. New substances are formed from
this reaction. On the other hand, other choices given are just physical changes
because only the shape or the physical form of the substances are being
changed. An example of a physical change is cutting a paper.
Answer: The correct option is 
Explanation:
Atomic mass of calcium ,Ca = 40.07 g/mol
Atomic mass of chlorine ,Cl = 35.5 g/mol
Molar mass of
:
= (Atomic mass of Ca+2 × (Atomic mass of Cl))
= (40.07 g/mol + (2 × 35.5))=111.07 g/mol

Hence, the correct option is 
You should should on yourself, treat yourself
Hangout with your friends and family, distract yourself
It’s okay to be sad for a couple days but be strong
You got this! :)