An unknown substance has a mass of 21.7 g. The temperature of the substance increases by 19.7°C when 165 J of heat is added to the substance. The table lists the specific heats of select substances.

Astudent carefully transfers 30 g of water and 30 g of alcohol in a glass tube, forming two layers and filling the tube completely. after sealing the tube, the student mixes the solutions, and notices a bubble that forms in the tube. what is the mass of the contents in the glass tube after mixing?

Ageochemist examines a piece of metal that he found in the soil. he performs tests to identify the metal from its density, electrical conductivity, and melting point. which statement best describes his investigation? a. he is determining physical properties that are sufficient to identify the metal. b. he is determining chemical properties that are sufficient to identify the metal. c. he is determining physical properties that are insufficient to identify the metal. d. he is determining chemical properties that are insufficient to identify the metal.

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?