WHAT IS THE COLOUR CHANGE WHEN WE ADD PHENOLPTHALEIN TO ACIDS AND BASES?

When we add phenolpthalein to acids it becomes colourless. When we add phenolpthalein to bases, the clour turns to MAGENTA. 

WHAT HAPPENS WHEN CARBONATES REACT WITH ACIDS?

Well it is mostly possible with metallic carbonates. When carbonates react with acids they give salt, water and carbon dioxide is released. Remember acids have replaceable hydrogen atoms.
So :
Metallic carbonates + acids = salt + water + carbon dioxide

CAN I GET SOME FORMULAS FOR SPEED, TIME AND DISTANCE?

Yes . The formula is speed= distance/ time. Distance= speed * time. Time = distance / speed.
So if a car runs 14 km in 2 hours(well just an example) then the the speed is 14/2 for Km/ph.
So the speed of the car is 7 km per hour. If a car covers 8 km in 2 hours then the distance would be speed * time. So it would be 16 km .

WHY DO ONIONS MAKE YOU CRY?

You  experienced the burning and tearing you get from the vapours. When you cut an onion, you break cells, releasing their contents. Amino acid sulfoxides form sulfenic acids. Enzymes that were kept separate now are free to mix with the sulfenic acids to produce propanethiol S-oxide, a volatile sulfur compound that wafts upward toward your eyes. This gas reacts with the water in your tears to form sulfuric acid. The sulfuric acid burns, stimulating your eyes to release more tears to wash the irritant away.

WHAT ARE ALKALIS?

Alkalis are the hydroxides of Calcium, Potassium and Sodium that are soluble in water. Ammonium hydroxide is also an alkali, but it does not contain a metal.

WHAT ARE BASES?

Bases are the oxides or the hydroxides of metals. They are chemically opposite to acids. Bases have a bitter taste. Some are very corrosive.

TELL ME ABOUT THE UNIVERSAL INDICATOR

The universal indicator that uses the scale if numbers to describe how acid or alkaline a substance is, rather than using colors. This scale is known as PH scale and the numbers are  called as PH numbers. Strong acids have the PH value of 0 or 1 while weak acids have PH values in the range of 4 to 6. Strong alkalies have the PH value of 13 to 14 and weak alkalies have their PH values in the range of 8 to 10. Neutral solutions like distilled water have a PH value of 7.