Which type of heat transfer takes place in this scenario? Sitting near a campfire

Conduction
Connection
Radiation

What is the specific heat of a substance that absorbs 2.5×10^3 joules of heat when a sample of 1.0 ×10^4g of the substance increases in temperature from 10°c to 70°c?

Phosphorous acid, h3po3(aq) , is a diprotic oxyacid that is an important compound in industry and agriculture. the values of phosphorous acid are 1.30 6.70 calculate the ph for each of the given points in the titration of 50.0 ml of 1.5 m h3po3(aq) with 1.5 m koh(aq) .

Asample of tin (ii) chloride has a mass of 0.49 g. after heating, it has a mass of 0.41 g.  what is the percent by mass of water in the hydrate?   %