A sample of N2H4 has a mass of 25g. Identify the numerical quantity that is needed to convert the number of grams of N2H4 to the number of moles of N2H4. (You do not need to do the actual calculation.)

Molecular Mass

Explanation:

It's asking for the numerical quantity. That quantity would be the Molecular Mass. Take the sample mass and divide it by the molecular mass to get the number of moles.

(14g N * 2) + (1g H *4) = 32g / mol of N2H4

To get # of moles, divide the sample mass by the molecular mass

25g / 32g = 0.78125 moles

where's the diagram?

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.