g + In a coffee-cup calorimeter, when 3.25 g of NaOH is dissolved in 50.00 g of water initially at 22.0 oC, the temperature of the solution increases to 24.8 oC. Calculate the q of the reaction in kJ/mol of NaOH. Assume that the specific heat of the solution is 4.184 J/g oC, and that there is no other heat transfer than that of the solution process itself.

THE STANDARD HEAT OF SOLUTION OF SODIUM HYDROXIDE IN WATER IS -7.68 KJ PER MOLE.

Explanation:

Variables:

Mass of NaOH = 3.25 g

Mass of water = 50 g

Initial temperature of water = 22°C = 22 + 273 K = 295 K

Final temperature of the reaction mixture = 24.8 °C = 24.8 + 273 K = 297.8 K

Assuming that:

1. specific heat of water = 4.184 J/g °C

2. total mass of the reaction mixture = 50 g + 3.25 g = 53.25 g

3. the rise in temperature = (297.8 K - 295 K ) = 2.8 K

4. Molar mass of sodium hydroxide = ( 23 + 16 + 1) = 40 g/mol

5. number of mole of sodium hydroxide = mass / molar mass

n = 3.25 g / 40 g/mol

n = 0.08125 moles

The rise in temperature for the reaction mixture produces how much of heat:

Heat = mass * specific heat * change in temperature

Heat = 53.25 * 4.184  * 2.8

Heat = 623.8344 J of heat.

Equation of reaction:

NaOH + H2O > NaOH + H2O + Heat

This is not a reaction but a dissolution as sodium hydroxide is very soluble in water and this reaction is exothermic where heat is given off.

So since 3.25 g having 0.08125 moles produces 623.8344 J of heat, 1 mole of the sodium hydroxide used will produce:

0.08125 mole of sodium hydroxide = 623.8344 J of heat

1 mole of sodium hydroxide = ( 623.8344 / 0.08125 J of heat

= 7677.96 J of heat per mole of sodium hydroxide.

= 7.68 kJ of heat

So therefore, the standard heat of solution of sodium hydroxide in water is -7.68 kJ of heat since its an exothermic reaction.

"hydrogen bonding is the attraction of h atoms in the water molecule (slight + charge) to o atoms in a neighboring water molecule (slight - charge); it is a weak interatomic force. but it is still strong enough to the water molecules "stick" together."

the food using pesticides in the future will harm you by giving you diseases like cancer or something since they have things that we should not eat in it like chemicals or pesticides. that is why organic food is more expensive because they take the time to make it right and healthy for you to eat.

explanation: