Need Chemistry help ASAP! Which of the following statements regarding chemical equilibrium is NOT necessarily true? A.) Equilibrium is shown using a double arrow.
B.) When a system is at equilibrium, it continues to react both ways (forward and reverse).
C.) At equilibrium, the amounts of reactants equal the amounts of products. D.) At equilibrium, particle-level changes are occurring.

Need an answer as soon as possible! Thanks so much!

The answer is

OSHA standards appear in the Code of Federal Regulations (CFR) and was then broken down into two parts.

The explanation:

OSHA standards are rules that describe the methods that employers must use to protect their employees from hazards. There are OSHA standards for Construction work, Maritime operations, and General Industry, which is the set that applies to most worksites. These standards limit the amount of hazardous chemicals workers can be exposed to, require the use of certain safe practices and equipment, and require employers to monitor hazards and keep records of workplace injuries and illnesses

It contains standards to ensure a comfortable and high quality research tools like the databases. These standards are to be strictly monitored to ensure  the safety of workers.

The correct answer is 13 billion years ago.  

The Big Bang theory is the existing cosmological model for the apparent universe from the most primitive known periods via its consequent large scale evolution. The model illustrates that how the expansion of the universe took place from a very high temperature and high-density state and provides a complete illustration for a wide array of processes comprising the existence of cosmic microwave background, light elements, Hubble's law, and large scale structure.  

The complete measurements of the rate of expansion of the universe put the Big Bang at approximately 13.8 billion years ago, that is, thus regarded as the age of the universe.  

Answer:

Option  C

Explanation:

A buffer  aqueous solution  consists of  

a) either a weak acid along with its conjugate base  

b) or a weak base along with its conjugate acid.  

This is used to prevent change in the pH of a solution whenever an acid or a base is added. The pH of a buffer depends upon the ratio of base to acid and this ratio is determined by the Ka value and Henderson-Hasselbalch equation. An ideal buffer has equal amounts of acid and conjugate base

Hence, option C is correct

Answer : The temperature will be, 150 K

Explanation :

Charles' Law : This law states that volume of gas is directly proportional to the temperature of the gas at constant pressure and number of moles.

    (At constant pressure and number of moles)

or,

where,

= initial volume of gas = 2.0 L

= final volume of gas = 1.0 L

= initial temperature of gas = 300 K

= final temperature of gas = ?

Now put all the given values in the above formula, we get the final temperature of gas.

Therefore, the temperature will be, 150 K