Answer:
(i) Change in colour (ii) Change in temperature (iii) Formation of precipitate
Explanation:
(i) Change in colour: Reaction between lead nitrate solution and potassium iodide solution. Pb(NO3)2(aq)+2KI → PbI2(s)+2KNO3(aq) In this reaction, colour changes from colourless to yellow. (ii)Change in temperature: Action of dilute sulphuric acid on zinc. Zn(s) + H2SO4(aq) → ZnSO4(aq) + H2 In this reaction, heat is evolved (iii) Formation of precipitate: Action of barium chloride on sodium sulphate. BaCl2(aq) +Na2SO4(aq) → BaSO4(s) +2NaCl(aq) BaSO4(s)
Answer:
b. growth in the size of the mineral grains
Explanation:
Non-foliated texture shown by a metamorphic change is depicted by growth in the size of the mineral grains.
- Examples of non-foliated metamorphic rocks are quartzite and marble.
- In these metamorphic rocks, mineral grains are not aligned with their long axis.
- Non-foliated texture occurs under high temperature and low pressure conditions.
- As minerals are able to grow, the size can be used to show a metamorphic change.
Rock is a combination of two or more minerals, and it does not possess any specific chemical composition. It is present naturally in the environment. Some examples of rocks are limestone, granite, etc.,Limestone may contain minerals like calcite and aragonite. Each mineral has a specific chemical composition with a well defined crystalline structure.
Therefore, the correct option would be a. rock as rock is the naturally occurring solid mass made up of different types of minerals.
Answer:
Postassium bisulphate - KHSO4 - can be used as an food preservative to protect the food from micro-organisms.
