I need help with the bottom two pls The first answer I will mark brainliest

Exit what is the density of an object having a mass of 5.0 g and a volume of 45.0 cm3?

When a chemist collects hydrogen gas over water, she ends up with a mixture of hydrogen and water vapor in her collecting bottle if the pressure in the collecting bottle is 97.1 kilopascals and the vapor pressure of the water is 3 2 kilopascals, what is the partial pressure of the hydrogen?

Find the enthalpy of neutralization of hcl and naoh. 87 cm3 of 1.6 mol dm-3 hydrochloric acid was neutralized by 87 cm3 of 1.6 mol dm-3 naoh. the temperature rose from 298 k to 317.4 k. the specific heat capacity is the same as water, 4.18 j/k g. a. -101.37 kj b. 7055 kj c. 10,1365 kj