The half life of uranium- 238 is
4.46 x10^9 years
Explanation
Half life is the time taken for the radioactivity of a isotope to fall to half its original value.
The original mass of uranium-238 is 4.0 mg
Half of original mass of uranium = 4.0 mg /2 = 2.0 mg
since it take 4.46 x 10^ 9 years for the sample to half the half life of uranium -238 = 4.46 x10^9 years
Answer:
42.3moles
Explanation:
The chemical equation given in this question is as follows:
H2 + O2 → H2O
However, this equation is unbalanced, the balanced chemical equation is as follows:
2H2 + O2 → 2H2O
This equation shows that;
2 moles of hydrogen gas (H2) will produce 2 moles of water (H2O)
Hence, If 42.3 moles of water (H2O) are produced, 42.3 × 2/2
= 42.3moles of hydrogen was reacted.
Answer: Silver has an atomic mass of aproximately 107.9.
Explanation:
1 mole of silver atoms = 107.9g and there are 6.02x10^23 atoms in one mole.
Answer:
Explanation:The Î""G°′ of the reaction is −7.180 kJ·mol−1. Calculate the equilibrium constant for the reaction at 25 °
Answer: Option (B) is the correct answer.
Explanation:
An aqueous solution that consists of a mixture of weak base and its conjugate acid or a weak acid and its conjugate base is known as a buffer.
When we add a strong acid or base into this mixture then the change in pH of this mixture is very small.
In a buffer solution, pH depends on the ratio of concentration of base divided by concentration of acid.
It is known that for a given temperature, the value of 
remains constant.
Therefore, relation between pH and will be as follows.
pH = 
Thus, we can conclude that the purpose of an acid-base buffer is to maintain a relatively constant pH in a solution.
