Which formula represents a hydronium ion?

(1) H3O + (3) OH-

(2) NH4 + (4) HCO3-

Which of the following involve chemical changes? 1. a carrot being digested 2. a piece of wood burning 3. a piece of chocolate melting

The colour change of methyl orange with neutral substance

What is the difference between boyle temperature and critical temperature?

A sample of Ca (OH) 2 is considered to be an Arrhenius base because it dissolves in water to yield A. Ca2 + ions as the only positive ions in solution B. H3O + ions as the only positive ions in solution C.

a sample of a gas occupies 1.40 x 10^3 mL at 25°C and 760 mmHg. what volume will it occupy at the same temperature and 380 mmHg

One molecule of caffeine contains 8 atoms of carbon, 10 atoms of hydrogen, 2 atoms of oxygen, 4 atoms of nitrogen. write the formula for caffeine with the elements in the order they are given.

A piece of magnesium metal is heated in the presence of chlorine gas, and a reaction takes place. What compound will most likely be produced? A. Mg2C1 B. MgCl3 C. MgCl2 D. MgCI

What is the pressure of the gas in this mercury manometer if h = 81 mm and atmospheric pressure is 749 mmHg

A microscope containing two or more lenses is an

What word means the remains or imprint of once living organisms found in layer of rock