Calculate the enthalpy change when 2 l of liquid nh3 is burned in air to give n2 (g) and h2o (g). express your answer using two significant figures.

One mole of liquid water and one mole of solid water have different

Where is the asteroid belt located?

What is the pH of a solution with [H+]=6.2x10-9 M?

The heat of fusion of a substance is the energy measured during a 1. phase change 2. temperature change 3. chemical change 4. pressure change

Which of the following is equal to 0.45 mm3? (B, right?) 4.5 x 10-7 m3 4.5 x 10-10 m3 4.5 x 10-7 cm3 4.5 x 10-3 cm3

What is the pressure, in mm Hg, of 2.50 moles of an ideal gas if it has a volume of 50.0 liters when the temperature is 27.0° C?

What element has the same valence electrons as carbon A) N B) AI C) Si or D) Be

What element is represented by the following electron configuration: 1s22s22p63s23p64s23d4 Question 2 options: Cr Ca Ge Ar

He substance, cocl2, is useful as a humidity indicator because it changes from pale blue to pink as it gains water from moist air. What is its name?

The weighted average atomic mass of an element depends upon the a. relative abundance of protons in the element b. mass and relative abundance of each isotope of that element c. mass and relative abundance of each neutron of that element d.