a) Từ các đơn chất có thể điều chế hợp chất hoá học.

Pưhh: Fe + Cl₂ --> FeCl₃

b) Từ hợp chất hoá học có thể điều chế các đơn chất.

Pưhh: H₂O ---đp---> H₂ + O₂

c) Từ hợp chất hoá học này có thể điều chế hợp chất hoá học khác.

Pưhh: Al(OH)₃ -t^o-> Al₂O₃ + H₂O

a,\(2KMnO_4\underrightarrow{^{to}}K_2MnO_4+MnO_2+O_2\)

a___________1/2a_______1/2a_______

\(2KClO_3\underrightarrow{^{to}}2KCl+3O_2\)

b___________b______

\(m_{Cr}=m_{K2MnO4}+m_{MnO2}+m_{KCl}\)

\(\Leftrightarrow197.\frac{1}{2}a+87.\frac{1}{2}a+74,5b\)

\(\Rightarrow142a+74,5b\)

b,\(m_{K2MnO4}+m_{MnO2}=m_{KCl}\)

\(\Leftrightarrow142a=74,5b\)

\(\Rightarrow\frac{a}{b}=\frac{74,5}{142}=\frac{149}{284}\)

Tìm và chữa lỗi sai

1.          Ho Chi Minh City, which named is after President Ho Chi Minh, is quite a young city.

                  A                           B                C                                                     D

2.          The child were told to apologize for being rude to his brother.

                 A(were-> was)               B               C         D

3.          When he arrived at the furniture shop, people had been sold the table he wanted.

                                    A            B                                     C                                   D

4.          The first May Day celebrated in England in 1890.

            A             B(celebarted-> was celebrated)         C                      D

5.          Most of them were build in the nineteenth century and some are very grand.

                  A                      B(biuld->built)    C                                       D

6.          In many universities, English taught to students althoughName=7; HotwordStyle=None;  it is not the native language.

            A            B(taught->is taught)            C                             D

7.          Two prisoners were hang this morning by the Taliban.

                      A             B(were hang->were hung)           C      D

8.          Daisy's ring is make of gold.

            A             B   C(is make-> is made)     D

9.          The literal work “Hamlet” was wrote by William Shakespeare.

          A      B(was wrote-> was written)   C                        D

10.      Chinese is studying by Henry every night.

                      A     B(studying-> studied)             C             D

11.      More people are infecting with HIV this year than they were 5 years ago.

           A                 B (infecting -> infected)           C                  D

12.      The meeting was be rearranged shortly before it had been due to take place.

            A(was be->was)                         B       C                               D

13.      Every possible effort were made by the orphanage to find the boy’s parents.

            A                      B (were -> was)                 C              D

14.      Cheques should only be accept with proof of identity.

                  A            B( be accept -> be accepted)             C      D

15.      Dent station is situated on the Seattle to Carlisle railway line, said be the most scenic in the

                   A                      B                  C(be->to be)            D

country.

16.      Do not blame me if the tin-opener is break.

            A         B           C                            D(break-> broken)

17.      This class has canceled because too few students had registered before registration closed.

          A(canceled-> been canceled)                B        C                  D

18.      This building will have finished by the end of 2020.

     A(will have finished-> will have been finished)        B          C               D

19.      A new road is built across this field next six months.

           A(is built-> will be built)                   B           C           D

20.      All his attempts are supporting heartily by his relatives and neighbors

           A(are supporting-> are supported)             B                     C                     D

Chúc bạn học tốt!

1067 gam => Đề sai.

Bài 1:

\(CTTQ:Al_xO_y\)

Theo QTHT, ta có:

\(x.III=y.II\Leftrightarrow\frac{x}{y}=\frac{II}{III}=\frac{2}{3}\)

=> x=2, y=3

\(CTHH:Al_2O_3\)

\(CTTQ:Zn_xCl_y\)

Theo PTHH, ta có:

\(x.II=y.I\Leftrightarrow\frac{x}{y}=\frac{I}{II}=\frac{1}{2}\)

=> x=1, y=2

\(CTHH:ZnCl_2\)

Câu 6:

\(V_{hh}=n_{hh}.22,4=\left(0,1+0,2\right).22,4=6,72\left(l\right)\)

=> Câu C

\(CTPT:Al_xO_y\\ Theo.QTHT\\ \Rightarrow x.III=y.II\Leftrightarrow\frac{x}{y}=\frac{II}{III}=\frac{2}{3}\\ \rightarrow CTHH:Al_2O_3\rightarrow A\)

Gọi CTHH là Al_xO_y

Theo quy tắc hóa trị ta có:

\(x\times III=y\times II\)

\(\Rightarrow\frac{x}{y}=\frac{II}{III}=\frac{2}{3}\)

Vậy CTHH là Al₂O₃

Chọn A

Al_xO_y

Theo QTHT, ta có:

III.x = II.y => \(\frac{x}{y}=\frac{2}{3}\) => x=2; y = 3

Vậy: CTHH là Al₂O₃ => chọn A

2R+2 H2O--->2ROH+H2

n\(_{H2}=\frac{2,24}{22,4}=0,1\left(mol\right)\)=>m\(_{H2}=0,2\left(g\right)\)

Theo pthh

n\(_R=2n_{H2}=0,2\left(mol\right)\)

M\(_R=\frac{4,6}{0,2}=23\)

=> R là Na

Theo pthh

n\(_{NaOH}=2n_{H2}=0,2\left(mol\right)\)

C% NaOH=\(\frac{0,2.40}{200+4,6-0,2}.100\%=3,91\%\)

NaOH +HCl---->NaCl +H2O

Theo pthh

n\(_{HCl}=n_{NaOH}=0,2\left(mol\right)\)

V\(_{HCl}=\frac{0,2}{2}=0,1\left(l\right)=100ml\)

Chúc bạn học tốt