Endothermic and Exothermic reactions

In (a)   reactions heat energy is absorbed.

Panam carries out an exothermic reaction, which preliminary work can she do before the experiment to tell that heat is generated?

• using a thermometer

• using a stop watch

• using a water bath

• none

In serbet sweets there is a mixture of dry (a)   and sodium hydrogen carbonate.

When we eat refreshing sweets the chemicals mix with the (a)   in our mouth.

Ice melting is an example of (a)   reaction.

Ice melts due to:

• vibration of particles

• gain in kinetic energy

• both

• none

In ice packs, water and ________________ are present in two compartments.

• lead nitrate

• copper nitrae

• silver nitrate

• ammonium nitrate

The ice pack absorbs _________________ from the skin.

• cold

• heat

• both

• none

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-3

Ali is mixing chemical A with chemical B and notices a fall in temperature, while writing the conclusion he decides that it is a (a)   reaction.

While eating refreshing sweets we feel cool because ____________ is absorbed from our mouth.

• saliva

• heat

• cold

• none