57.00 mL of a concentrated ethanol solution is added to a container to make 1.75 L of a 0.19 M diluted solution. What was the initial concentration of the ethanol?

Which of the following is a testable hypothesis? a. if i brush my teeth, i will get fewer cavities than if i don't brush my teeth. b. green toothpaste tastes better than blue toothpaste or red toothpaste. c. smart, careful, healthy people always brush their teeth. d. it's wrong to not brush your teeth before you have an important conversation with someone.

Asmall amount of a solid is added to water. the observation made after fifteen minutes is shown in the figure. which of these solids has been probably added to water? a) oil b) sand c) sugar d) wood chips

An alloy contains 66 g of pure zinc. what is the percentage of zinc in the alloy? express your answer to two significant figures and include the appropriate units.