Which is NOT a chemical change? a. a piece of wood is burned b. an egg is cooked c. a bar of iron rusts d. ingredients for a cake are stirred together
Samples of gases containing nitrogen and oxygen were decomposed by electricity and the volume of each gas produced was measured. Based on these results, what is the correct chemical formula for Sample 4? Sample Volume of Nitrogen (L) Volume of Oxygen (L) 1 2.00 3.02 2 1.01 1.99 3 1.98 4.99 4 1.02
The law of ____ states that a compound is always composed of the same elements in the same proportion by mass.
Which of the following substances is a mixture? a. Baking soda b. Gasoline c. Salt d. Sugar
Matter that has a uniform and unchanging composition is known as a(n) ____.
What is the state of matter that has a definite shape and definite volume?
Which is an intensive physical property? a. color b. mass c. length d. volume
Which is a compound? a. sodium b. sea water c. carbon dioxide d. brass
How many individual atoms make up one unit of aluminum chloride, AlCl3?
A chemical composition of two or more different elements joined together in fixed proportions is known as a(n) ____.
What is the separation technique that identifies parts of a mixture based on how fast different compounds move across a material?
Which of the following formations is a physical property of copper? a. A deep blue solution when in contact with ammonia. b. A new substance when combined with nitric acid. c. A green copper carbonate compound when in contact with moist air. d. A formation of a drill gauge and wire.
What is the state of matter that has an indefinite shape and indefinite volume?
Identify both a physical change and a chemical change that could be done to a piece of fruit.
If 26 grams of potassium are burned in air to produce 12 If 26 grams of potassium are burned in air to produce 12.2 grams of potassium oxide, what is the mass of oxygen from the air that is needed?
Is a solution a homogeneous or heterogeneous mixture?
A 20-g sample of magnesium reacts with bromine to form 32 g of magnesium chloride. How many grams of chlorine are used in the reaction?
What is the percentage by mass of oxygen if 6 What is the percentage by mass of oxygen if 6.23 g of it reacts with 12.25 g of nitrogen to form a compound of mass 18.48 g? Also, calculate the percentage by mass of nitrogen in the compound.
Copper sulfide is formed when copper and sulfur are heated together Copper sulfide is formed when copper and sulfur are heated together. In this reaction, 152 g of copper reacts with 55 g of sulfur. After the reaction is completed, 8 g of sulfur remains unreacted. What is the mass of copper sulfide formed?
A 25. 3 g sample of an unknown compound contains 0. 8 g of oxygen A 25.3 g sample of an unknown compound contains 0.8 g of oxygen. What is the percent by mass of oxygen in the compound?