What are the four signs of a chemical reaction

When the pressure that a gas exerts on a sealed container changes from blank torr to 900 torr the temperature changes from 300 k to 450 k

If you pour 9.0 g of sodium chloride into water to produce 240 mL of solution, what will the molarity be?

1 2 3 4 5 6 7 8 9 10 The diagrams show gases that are stored in two separate but similar containers. 2 identical containers have gas particles, represented by small balls with arrows representing movement in random directions.

In a hypothetical atom, electron Z transitions between energy levels, giving off an orange light in the transition. In the same atom, electron D gives off a violet light when it transitions between energy levels.

How is the bright line spectrum of carbon produced?

When red litmus paper is added to limewater, then what will be the change in litmus paper? Give reason. Write the chemical formula of limewater also.

Explain why the lattice energy of CaSe is approximately 4 times as large as that of KBr. Check all that apply. Check all that apply.

A 1.0 g sample of food reacts with oxygen in a calorimeter containing 500 g of water. The temperature rises 10°C. What is the energy content of the food?

Looking at the diagram showing hydrochloric acid being added to water. Which statement best explains what is taking place

How many dozens of particles of dust are in 2.45 grams if each dust particle has a mass of 2.51 x 10-4 grams?