CBSE Class 10th Solutions Maths, Science

Questions 1. Why should curd and sour substances not be kept in brass and copper vessels? Ans: Curd & Sour substances are acidic in nature, it will react with brass & copper these acidic substances combine with metal. This reaction turns food to poison which damage people’s health. 2. Which gas is usually liberated when an acid reacts with a metal? Illustrate with an example. How will you test for the presence of this gas?  Ans: When an acid reacts with any metal, salt and hydrogen gas are formed. Metal + Acid  →  Salt + Hydrogen gas 3. Metal compound A reacts with dilute hydrochloric acid to produce effervescence(bubbles in liquid). The gas evolved extinguishes a burning candle. Write a balanced chemical equation for the reaction if one of the compounds formed is calcium chloride. Ans: As metal compound released is Calcium Chloride the gas evolved here is CO2. Hence metal A should be Calcium Carbonate. Hence the...

Class 10th Science Chapter 2 Sour liquid-Acidic in nature,  Bitter liquid - Basic in nature If you are having acidity among Lemon, Vinegar   , Baking soda  , you should take Baking Soda coz its Basic in nature other 2 are acidic in nature.  Acid turns Blue litmus paper into Red. Basic does opposite . Litmus Paper is made by soaking the absorbing paper in litmus solution (dye extracted from lichen((fungi+alga) living together as 1. Lichen is a plant belonging to the division Thallophyta,)) When the litmus solution is neither acidic nor basic, its colour is purple. There are many other natural materials like red cabbage leaves, turmeric, coloured petals of some flowers such as Hydrangea  , Petunia   and Geranium  , which indicate the presence of acid or base in a solution. These are called acid-base indicators or sometimes simply indicators Q U E S T I O N    1. You have been provided with three test tubes. One of them contains d...