9) What mass of oxygen is formed when 735 g of potassium chlorate
decomposes?
2 KCIO3 + 2 KCI + 3 O2
(3)
10)
What mass of hydrogen is produced when 195 mg of potassium is added to
water?
2 K + 2 H2O → 2 KOH + H2
(3)
11)
How much calcium oxide is produced by heating 50 g of calcium carbonate?
CaCO3 + CaO + CO2
(3)
12)
What mass of magnesium oxide is formed when 6 g of magnesium reacts with
oxygen?
2 Mg + O2 + 2 Mgo
(3)

Acylinder is filled with 2.00 moles of nitrogen, 3.00 moles of argon and 5.00 moles of helium. if the gas mixture is at stp, what is the partial pressure of the argon

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.

Which are forms of frozen water? check all that apply. dew frost hail rain sleet