a) 1. \(N_2+3H_2⇌^{t^o;xt;P}2NH_3\)

2. \(NH_3+HCl\rightarrow NH_4Cl\)

3. \(NH_4Cl\underrightarrow{t^o}NH_3+HCl\)

4. \(MnO_2+4HCl\rightarrow MnCl_2+Cl_2+2H_2O\)

5. \(Cl_2+NaOH\rightarrow NaCl+NaClO+H_2O\)

6. \(2NaCl+2H_2O\underrightarrow{đpdd}2NaOH+Cl_2+H_2O\) ( có màng ngăn )

b) 1.CH3-C\(\equiv CH\) \(+4O_2\rightarrow3CO_2+2H_2O\)

2. \(CO_2+2NaOH\rightarrow Na_2CO_3+H_2O\)

3. \(Na_2CO_3+H_2SO_4\rightarrow Na_2SO_4+H_2O+CO_2\uparrow\)

4. \(Na_2SO_4+BaCl_2\rightarrow BaSO_4\downarrow+2NaCl\)

Sai đề rồi 

1. even though : dẫu rằng 

2. without delay : ko trì hoãn ; ngay lập tức 

1.B homeworks -> homework

2.A aren't -> are

3.C have -> has

4.A much -> many

5.D on -> by  

\(a^4+a^3+a^2+a=a^3\left(a+1\right)+a\left(a+1\right)=\left(a^3+a\right)\left(a+1\right)=a\left(a^2+1\right)\left(a+1\right)\)

\(P=x^2+y^2=\left(x+y\right)^2-2xy=9^2-2.14=81-28=53\)

Chọn B

Coi \(P=P\left(x\right)\)

Tại \(x=99\) thì \(100=x+1\) . Khi đó ; ta có : 

\(P\left(99\right)=x^5-\left(x+1\right)x^4+\left(x+1\right)x^3-\left(x+1\right)x^2+x\left(x+1\right)-9\)

\(=x^5-x^5-x^4+x^4+x^3-x^3-x^2+x^2+x-9\)

\(=x-9=99-9=90\)

Chọn C