đốt cháy 0.62 g HCHC X , thu được 0.9 g H20 và 0.88 g CO2.Mặt khác nếu đốt cháy 0.31 g chất X với CuO thì thu được 112 ml N2(dktc).Biết rằng 0.173 g hơi X chiếm 125ml. Công thức phân tử x :

Choose the best answer.

I think you should buy _____  pack of mineral water instead. And you can also buy _____  snacks such as potato crisps, 3 kilos of mandarins, 2 kilos of apples, 3 bunches of bananas, ______  cookies and soft candies.

Choose the best answer.

We should decorate our living room with _____ orange banner. We also need ________  ribbons, balloons, party hats and costume.

Choose the best answer.

I think that ______ cauliflower is not enough for 3 people. Let’s buy one more.