Why in one sentence is the case вопросы used, while in another, nearly similar sentence вопросов is used instead?

[scot]

Here is the first sentence: почему ты задаёшь все эти вопросы?
And the second: почему ты задаёшь так много вопросов?

[nobody]

“Many” in Russian is expressed as много + genitive. Think “a lot” + of… or “a great deal” of…
Много = a lot
Вопросов = of questions

Вопросы would be just “questions” (accusative case in the example)

[scot]

Ah, now I understand. Thank you!