Question

VERY SHORT QUESTIONS (1 Mark)
What changes do you observe in the iron nails and colour of copper
sulphate solution, if iron nails are dipped in Cuso, solution for 15
minutes ?
Identify the chemical change :
2.
Melting of ice or conversion of milk into curd.
3.
Why is respiration considered an exothermic reaction ?
4.
Why do copper vessel lose shine when exposed to air ?
5.
Potato chips manufacturers fill the packet of chips with nitrogen ga
Why?
6.
Why we store silver chloride in dark coloured bottles ?
7.
Write a chemical equation of double displacement reaction.​

Answer 1

1 displacement reaction
2 physical change, chemical change
3 because the carbohydrates break down to form glucose which combine with oxygen present in the body
4 because copper react with the gases present in the atmosphere
5 because to prevent them from rancid
6 because when it expose to air it decomposes to silver
7 barium chloride reacts with sodium sulfate to give barium sulphate (white ppt) + sodium chloride