Which of these is true about pure substances?

A) They can only contain one type of atom

B) They may contain one type of atom or one type of molecule

C) They can contain different types of atoms and molecules

D) They can contain only one type of molecule

When temperature increases, what happens to the molecules in a chemical reaction?

In terms of energy, how would you classify the following chemical reaction? 2Cu + O2 - > 2CuO + 315 kJ a. endothermic b. exothermic c. both endothermic and exothermic d. neither endothermic nor exothermic 2.

A solution that is a 4 on pH scale is a

Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule.

What model did Rutherford make?

What is the molarity of a solution that has 548 grams of HCl dissolved in 1.50 l water?

Steve puts some cheddar cheese in a pan on the stove and starts to melt it. After a little while, there is a layer of oil floating on top of the cheese. From the way the cheese melted, Steve knows it is a A Element B Solid C Mixture D Pure Substance.

Which experimental feature of the MALDI-MS technique allows the separation of ions formed after the adduction of tissue molecules? A) Distance travelled by ions depends on the ion charge. B) Velocity of ions depends on the ion mass-to-charge ratio.

Which temperature is required for the cell potential to be the standard cell potential? A) - 273°C B) 100°C C) 25°C D) 0°C

1. the purpose of the aqueous solutions in a galvanic cell is to? a. provide ions to be oxidized and reduced b. provide a path for the free flow of electrons c. maintain charge balance in the cell d. correct any volume changes in the cell 2.