# units

## How Much Does a Gallon of Water Weigh? Easy Calculation

Question: How much does a gallon of water weigh? Answer: A US gallon of water weighs 8.34 lbs or 3.78 kg at 62 °F (17 °C). An imperial gallon (UK) weighs 10.022 lbs or 4.546 kg, at its most dense temperature, which is 2.20456 lbs / L at 4 °C […]

## Karat vs Carat – Understand the Difference Between Karats and Carats

What’s the difference between karats and carats? Are they the same? The terms karats and carats are both used to refer to bling in the jewelry trade and in geology, but the words don’t mean the same thing. A carat is a unit of mass used in the jewelry industry […]

## Physical Constants, Prefixes, and Conversion Factors

Here are some useful physical constants, conversion factors, and unit prefixes. They are used in many calculations in chemistry, as well as in physics and other sciences. Useful Constants Acceleration of Gravity 9.806 m/s2 Avogadro’s Number 6.022 x 1023 Electronic Charge 1.602 x 10-19 C Faraday Constant 9.6485 x 104 […]

## Concentration Units For Solutions1

Chemistry is a science which deals a lot with solutions and mixtures. Knowing just how much of one thing is mixed in with a solution is an important thing to know. Chemists measure this by determining the concentration of the solution or mixture. There are three terms that need to […]

## Know Your Concentrations – Difference Between Molarity and Molality

Molarity and molality are both measurements dealing with concentration of solutions in chemistry. When you see a bottle marked with either a capital M or a lower-case m, what does it mean? Is there a difference? Yes there is a difference. Molarity is the most common concentration measurement and denoted by […]