Câu 36: _VD _Hình lập phương có thể tích là 1253 thì diện tích đáy là: A. cm2 B. 5cm2 C. 25cm2 D. 52cm2

c

Explanation:

Cạnh của hình lập phương là

³\(125 = 5cm

Diện tích đáy của hình lập phương là

5²=25cm²

Đáp án C

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2