It says on google
<span>An acid-base indicator (e.g., phenolphthalein) changes color depending on the pH. Redox indicators are also frequently used. A drop of indicator solution is added to the titration at the start; when the color changes the endpoint has been reached, this is an approximation of the equivalence point.</span>
Answer: adding
Explanation:
Because it takes thermal energy to power it
<u>Answer:</u> The density of liquid is 
<u>Explanation:</u>
We are given:
Mass of cylinder, 
= 65.1 g
Mass of liquid and cylinder combined, M = 120.5 g
Mass of liquid, 
= 
To calculate density of a substance, we use the equation:
We are given:
Mass of liquid = 55.4 g
Volume of liquid = 49.3 mL = 
(Conversion factor: 
)
Putting values in above equation, we get:
Hence, the density of liquid is
In your choices, the best answer is the mass of the reactants and the mass of the products are no equal. The chemical equilibrium can take place in a close system and can not be affected by catalyst and is a reversible reaction. The best describe should be the concentration of reactants and products are constant.
Answer is: <span>it comes at the right time.
Some of the chemistry discoveries that come in right time (with enough informations, knowledge and right technology to use that discovery) are: </span>Periodic Table of the Elements, discovery of electron, proton, neutron, radioactivity, pasteurization, t<span>he Haber-Bosch process.</span>
