Which if the following is a base
a) substance d contains carbon hydrogen oxygen and nitrogen
b) substance b gives off oh- ions that combine with h+ ions when dissolved in water
c) substance c is formed drom the reaction of an acid and base
d) substance a gives off h+ ions that combine with oh- ions when dissolved in water

B is the most probable answer.

A base is a substance that accepts hydrogen ions. When a base is dissolved in water, the balance between hydrogen ions and hydroxide ions shifts. The base "soaks up" hydrogen ions and the result is a solution with more hydroxide ions than hydrogen ions. This kind of solution is an alkaline solution.

Examples of bases include:

1. Potassium hydroxide

2. Ammonia

3. Acetone

5. Pyridine

6. Rubidium hydroxide

7. Sodium hydroxide

8.Zinc hydroxide

9. Methylamine

10. Lithium hydroxide.

practical process described pest part of scientific investigation.

because practical knowledge is powerful then therotical knowledge.

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