Change of state occurs when heat is supplied or removed from a substance.
<h3>What is change of state?</h3>
Change of state refers to the changes that occur when a substance changes from one physical state to another due to changes in its temperature.
It is also known as phase change.
Phase Change can also be defined as change from one state to another without a change in chemical composition.
Some of the phase changes include:
- Freezing: when liquid changes to solid
- Condensation: when gas changes to liquid
- Melting: when solid changes to liquid
- Evaporation: when liquid changes to gas
The other terms associated with phase change include:
- Boiling point: the temperature at which vapor pressure becomes high that causes bubbles to form inside the body of the liquid
- Freezing point: temperature wherein a liquid solidifies
- Melting point: the temperature at which solid turns into a liquid.
Learn more about change of state at: brainly.com/question/18372554
<h3><u>Answer;</u></h3>
D. It decreases and the pH increases.
<h3><u>Explanation;</u></h3>
- pH is a measure of the hydorgen ion concentration of a solution. Solutions with a high concentration of hydrogen ions have a low pH and solutions with a low concentrations of H+ ions have a high pH.
- <em><u>[H+] and [OH-] are inversely related. Therefore; As the concentration of H+ increases the pH decreases. Since the concentrations of H+ and OH- are inversely proportional, as one goes up, the other goes down. </u></em>
- <em><u>Therefore, an increase in OH- concentration will correspond to an increase in pH and a decrease in the concentration of H+.</u></em>
Adenine , guanine, cytosine and thymine
Given :
A certain compound contains 4.0 g of calcium and 7.1 g of chlorine.
Its relative molecular mass is 111.
To Find :
Its empirical and molecular formulas.
Solution :
Moles of calcium , 
.
Moles of chlorine , 
.
The ratio calcium and chlorine is 1 : 2 .
So , the empirical formula is 
.
Now , molecular mass of is :
So , 
Therefore , the molecular formula is also .
Hence , this is the required solution .
