How much heat (in kilojoules) is evolved or absorbed in the reaction of 1.90g of na with h2o ?

2na(s) + 2h₂o(l) -> h2(g) delth = -368.4kj.

The heat of the reaction is an extensive property: it is proportional to the quantity of the quantity that reacts.

The change in enthalpy is a measured of the heat evolved of absorbed.

When the heat is released, the change in enthalpy is negative.

The reaction of 2 moles of Na develops 368.4 kj of energy.

Calculate the number of moles of Na in 1.90 g to find the heat released when this quantity reacts.

Atomic mass of Na: 23 g/mol

#mol Na = 1.90 g / 23 g/mol = 0.0826 mol

Do the ratios: [368.4 kj/2mol ] * 0.0826 mol = 15.21 kj.

Then the answer is that 15.21 kj of heat is released (evolved)

A3.5 gap gps and your masters degree

True, the standard unit for volume is liters which can be represented by either a lower case "l" or a capital "l"