Calculate the standard enthalpy change for the following reaction at 25 degrees Celsius. MgCl2 + H2O--> MgO + 2HCl

ls this following sentence True or False? Most of an atom's volume is the space in which electrons move. True or False

What do the laws of conservation mean

Minerals are very useful to us. Which of the following is a false statement? A. Pyrite is an ore of gold and is used in jewelry making. B. Cobalt is not used in medicine. C. Quartz is used to make glass. D. Quartz is used to make glass.

What is the y component of the electron's velocity (sign included) when the electron hits the screen?

John Dalton believed that: A. Atoms are made of mostly empty space. B. Chemical changes are the result of different atomic combinations. C. Violent chemical reactions can divide atoms into smaller particles. D. All of the above.

A sample of NO2 in a 1550 mL metal cylinder at 70.26 kPa has its temperature changed from 480oC to - 237oC while its volume is simultaneously changed by a piston to 5114 mL. What is the final pressure in kPa?

How many grams of methane gas (CH4) are in a 15.8-liter sample at 1.2 atmospheres and 27°C? Show all work used to solve this problem

Oxygen forms a number of compounds with sulfur, many of which are quite reactive. One such compound is 57.20 % by mass S. Calculate the number of grams of oxygen present in a sample of this compound that contains 50.00 grams of S.

What is meant by "pressure of the atmosphere?" What causes this pressure?

A substance is analyzed and found to contain 85.7% carbon and 14.3% hydrogen by weight. A gaseous sample of the substance is found to have a density of 1.87 g/L, and 1 mol of it occupies a volume of 22.4 L.