Under what conditions the interaction - chlorine + hydrogen = hydrogen chloride takes place with an explosion: A: when stirring;
B: in the cold;
C: at maximum contact and in the dark;
D: at maximum contact and direct sunlight?
Task 2: In separate cups are placed a teaspoon of the substances salt, sugar, flour and baking soda. They are covered with vinegar. Which of the substances will interact with the vinegar at room temperature?
?

3: Under what conditions hydrogen and oxygen are obtained from water;
A: at room temperature
B: when cooling
C: in the dark
D: when an electric current flows?

4: Which of the following changes is not a sign of a chemical reaction:
A: Heat release
B: Stirring;
C: Light releasing
D: Dissolving sludge?