Which processes represent one chemical change

and one physical change?

(1) freezing and melting

(2) freezing and vaporization

(3) decomposition and melting

(4) decomposition and combustion

A gas mixture contains twice as many moles of o2 as n2. addition of 0.200 mol of argon to this mixture increases the pressure from 0.800 atm to 1.10 atm. how many moles of o2 are in the mixture?

A science teacher dissolved 50 grams of salt in 300 milliliters of water. he set the solution aside until all the water had evaporated. How many grams of salt should have been left in the glass container after the water had evaporated?

Nitrogen gas and hydrogen gas react to form ammonia according to the following thermochemical equation. 3H2+N2⟶2NH3ΔH=-96kJ Write the balanced chemical equation for a reaction involving these substances with the following change in enthalpy.

Vinegar is added to baking soda and bubbles of carbon dioxide rapidly form. A cloudy liquid is left behind.

Which of the following would have the highest viscosity? water honey salad oil alcohol

Write the mathematical expression that allows you to solve for the oh - concentration in water when you know only the h3o + concentration.

The role gravity played in the formation of the sun?

What kind of reaction occurs when you mix aqueous solutions of barium sulfide and sulfuric acid?

What is true about empathy? Most anyone can learn this skill. Not everyone can learn this skill. It is a desirable attribute. choices A and C

What effect can new observations have on a scientific theory