Give the reason why the empty crucible should be heated before starting the experiment

Arrange the events in the life of a star in the correct order. All that remains of the star now is the core. In some cases, the star turns into a black hole.

The standard internal energy change for a reaction can be symbolized as ΔU°rxn or ΔE°rxn. For the following reaction equations, calculate the energy change of the reaction at 25 °C and 1.00 bar. Sn (s) + Cl2 (g) - - - > SnCl4 (l) + H (KJmol) - 511.3.

When copper (II) oxide is heated with hydrogen gas, water and copper metal is produced. What mass of copper can be obtained if 32.0g of copper (II) oxide is used? A: 24.3g B: 25.5g C: 27.6g

What is the color of phenolphthalein and litmus paper in a solution of PH = 4?

An aqueous solution of potassium sulfate is allowed to react with an aqueous solution of calcium nitrate. identify the solid in the balanced equation.

Which of the following is a postulate of the kinetic-molecular theory? A. Gases are made up of particles that act like small, soft spheres that are always moving in a calculated fashion. B.

An atom's outermost electron arrangement determines how it interacts with other atoms. Which of the following atomic structures would be most likely to form an ionic bond? A. neon, which has eight outer electrons B.

The main acid in the stomach is hydrochloric acid (HCl). Which chemical equations show a reaction that occurs when someone takes an antacid? Check all that apply.

Which type of metals have high densities, strenght, and resistance to corrosion

White powder, when heated, produces a colourless gas and a black solid. Is the white powder and element?