Hydrogen gas is collected over water at 21 degrees Celsius. At 21 degrees Celsius the vapor pressure of water is 18.7 torr. If the barometric pressure is 758 torr, what is the pressure of hydrogen gas?

Calculate the estimated density of each ball. use the formula d = m/v where d is the density, m is the mass, and v is the volume. record your calculations in table a of your student guide. given that the density of water is 1.0 g/cm3, make a prediction about whether each ball will float in water. record your prediction in table a. what is the estimated density of the table tennis ball? record your answer to the nearest hundredth

Which of the following is a physical change? a.burning a piece of wood b.sawing a piece of wood in half c.rust forming on an iron fence d.a copper roof changing color from orange to green

Substance 33°f 100°f peanut oil solid liquid margarine solid liquid chocolate chips solid liquid which conclusion fits the data in the table? a. heat chemically changes chocolate and margarine. b. all solids become liquid at 100°f. c. removing heat from a substance it to melt. d. matter may change shape when it is heated.