Why is a single system of measurements necessary throughout the scientific community?

How many moles of gas are there in a 45.0 l container at 25.0°c and 500.0 mm hg?

Which is an example of the use of activation energy? A. Plugging in an iron B. Playing Basketball C. Holding a match to a paper D. Eating

Compare the function of a switch in an electric circuit to the function of a water faucet. How are they different?

Describing physical and chemical changes: An industrial chemist is studying a sample of an unknown metal. Describe two ways he could change the metal physically and two ways he could change the metal chemically to try to identify it.

What to know for acids and bases

A substance contains 36.1 percent calcium and 63.9 percent chlorine by weight. What is the empirical formula of the given compound? A. CaCl B. Ca0.9Cl1.8 C. CaCl2 D. Ca2Cl4

A sample of bismuth weighing 0.687 g was converted to bismuth chloride by reacting it first with HNO3, and then with HCI, followed by careful evaporation to dryness. The mass of the bismuth chloride obtained was 1.032 g.

When 1 g of sodium chloride (NaCl) is placed in 100 g of water, a solution results. Once the solution is prepared, water is now considered what part of the solution?

1. How is pressure affected as depth increases? 2. As the sun heats the surface of the oceans, two layers of water result. What separates the layers? 3. How is temperature affected when? (a) the depth increases (b) the latitude increases 4.

Are nails in a jar with water a chemical change