N2H4 (Hydrazine) is a rocket fuel, it burns in O2 to give N2 and H2O N2H4 + O2 N2 + 2H2O

1.00 g of n2h4 is burnt in a bomb calorimeter an increase of temperature 3.51° C is recorded. The specific heat of calorimeter is 5.5 J k⁻¹ g⁻¹ . Calculate the quantity of heat evolved also calculate the heat of combustion of one mole of N2H4

You have 125g of a certain seasoning and are told that it contains 76.0 g of salt what is the percentage of salt by mass in this seasoning

Describe the difference between a. a hypothesis and a theory and b. an observation and an experiment.

The atomic radius of sodium is 186 pm and of chlorine is 100 pm. the ionic radius for na+ is 102 pm and for cl– is 181 pm. in going from na to cl in period 3, why does the atomic radius decrease while the ionic radius increases? a. the inner electrons in the sodium cation shield its valence electrons more effectively than the inner electrons in the chloride anion do. b. the inner electrons shield the valence electrons more effectively in the chlorine atom than in the chloride anion. c. the outermost electrons in chloride experience a smaller effective nuclear charge than those in the sodium cation do. d. the outermost electrons in chloride experience a larger effective nuclear charge than those in the sodium cation do. e. monatomic ions are bigger than the atoms from which they are formed.