Which of the following is not a sign that a chemical change has occurred?

-Change in energy

-Change in mass

-formation of precipitate

-Change in color

The volume of water that must be added in order to dilute 40mL of 9.0M HCl to a concentration of 6.0 M is closest to: (A) 10 mL (B) 20 mL (C) 30 mL (D) 40 mL (E) 60 mL

We use a kind of plant growth hormone to regular plant growth. We dissolve 5mg of the solution into 2kg of water. What is the dosage of the solution in ppm?

1) Identify the intensive properties of a sample of matter: A. mass B. hardness C. color D. volume E. reflectivity

Why do consumers feel warmer after eating a meal

Calculate the ph of a buffer that is 0.13m in lactic acid and 0.10m in sodium lactate.

Read the following passage: The movement of tectonic plates buries a rock deep inside Earth. Intense heat and pressure change the mineral composition of the rock and transform it into Rock A.

What is a change which forms one or more new substances?

Which changes occur as a cadmium atom, Cd, becomes a cadmium ion, Cd2+? (1) The Cd atom gains two electrons and its radius decreases. (2) The Cd atom gains two electrons and its radius increases.

Explain Charles law

2 H2 + O2 → 2 H2O What is the product of this chemical reaction