hòa tan hoàn toàn hổn hợp gồm Fe và Fe2O3 bằng dd axit clohiđric vừa đủ thu được 2,24 lít khí H2 (đktc) và dd A .Cho dd A phản ứng với 1 lượng vừa đủ với dd Bạc Nitrat thì thu được 86,1g kết tủa và dd B . Dd B được phản ứng hoàn toàn với 400ml dd Natri Hiđroxit thì được m g chất kết tủa . a, Viết các PTHH b, Tính thành phần % theo khối lượng của mỗi chất có trong hổn hợp c, Tính $C_{M}$ của dd Natri Hiđroxit d, tính m

1 câu trả lời

Đáp án + Giải thích các bước giải:

$a)PTHH:$

$Fe+2HCl\to FeCl_2+H_2\uparrow$

$Fe_2O_3+6HCl\to 2FeCl_3+3H_2O$

$FeCl_2+2AgNO_3\to Fe(NO_3)_2+2AgCl\downarrow$

$FeCl_3+3AgNO_3\to Fe(NO_3)_3+3AgCl\downarrow$

$Fe(NO_3)_2+2NaOH\to Fe(OH)_2\downarrow+2NaNO_3$

$Fe(NO_3)_3+3NaOH\to Fe(OH)_3\downarrow+3NaNO_3$

$b)n_{H_2}=\dfrac{2,24}{22,4}=0,1(mol);n_{AgCl}=\dfrac{86,1}{143,5}=0,6(mol)$

Theo các PT: $n_{Fe}=n_{FeCl_2}=n_{H_2}=0,1(mol)$

$\Rightarrow m_{Fe}=0,1.56=5,6(g)$

$\Rightarrow n_{FeCl_3}=\dfrac{1}{3}.(n_{AgCl}-2.n_{FeCl_2})=\dfrac{1}{3}(0,6-0,2)=\dfrac{4}{3}(mol)$

$\Rightarrow n_{Fe_2O_3}=\dfrac{1}{2}n_{FeCl_3}=\dfrac{2}{3}(mol)$

$\Rightarrow m_{Fe_2O_3}=\dfrac{2}{3}.160=106,67(g)$

$\Rightarrow \%m_{Fe_2O_3}=\dfrac{106,67}{106,67+5,6}.100\%=95,11\%$

$\Rightarrow \%m_{Fe}=100-95,11=4,89\%$

$c)$ Theo các PT: $n_{NaOH}=2n_{FeCl_2}+3n_{FeCl_3}=n_{AgCl}=0,6(mol)$

Đổi $400ml=0,4l\Rightarrow C_{M_{NaOH}}=\dfrac{0,6}{0,4}=1,5M$

$d)$ Theo các PT: $n_{Fe(OH)_2}=0,5n_{FeCl_2}=0,1(mol)$

$n_{Fe(OH)_3}=n_{FeCl_3}=\dfrac{4}{3}(mol)$

$\Rightarrow m_{\downarrow}=m_{Fe(OH)_2}+m_{Fe(OH)_3}=0,1.90+\dfrac{4}{3}.107=151,67(g)$

Vậy $m=151,67$

Câu hỏi trong lớp Xem thêm

I.  MULTIPLE CHOICE (8.0 points)

Mark the letter A, B, C, or D to indicate the word whose underlined part is pronounced differently front that of the rest in each of the following questions.

1. A. oceanic    B. remote    C. occasion    D. metro

2. A. festival    B. cultural    C. sculpture    D. virtual

Mark the letter A, B, C, or D to indicate the word that differs from the other three in the position of primary stress in each of the following questions.

3. A. external    B. determine    C. mysterious    D. customer

4. A. miraculous    B. individual    C. certificate    D. astronomy

Mark the letter A, B, C, or D to indicate the underlined part that needs correction in each of the following questions.

5. Now that the stress of examinations are over, we can go somewhere for our holiday.

                     A                     B                     C                     D

6. The English summer course will start in May 29th and finish in August.

                     A                     B                     C                     D

7. There were so a lot of people trying to leave the burning building that the police

             A                B             C

had a great deal of trouble controlling them.

                   D

Mark the letter A, B, C, or D to indicate the correct answer to each of the following questions.

8. The earthworm is a worm _______in moist, warm soil in many geographical areas.

    A. where is it found       B. is found

    C. and found it               D. which is found

9. Our flight from Amsterdam to London was delayed    the heavy fog.

    A. as a result     B. on account     C. instead of     D. due to

10. It is_______ to translate each lesson into your language. This is not a good way to study English.

    A. productive     B. unproductive     C. producing     D. unproducing

11. A good clock always keeps_______ time.

    A. certain    B. accurate    C. true    D. serious

12. It seems that the world record for this event is almost impossible to_______.

    A. meet    B. compare    C. beat    D. balance

13. The soldier was punished for_______ to obey his commanding officer's order.

    A. refusing    B. regretting    C. objecting    D. resisting

14. It is believed that she'll be a billionaire by the time she_______ forty.

    A. is    B. was    C. will be    D. would be

15. Some of the passengers spoke to reporters about their_______ in the burning bus.

    A. occasion    B. happening    C. event    D. experience

16. _______the rise in unemployment, people still seem to be spending more.

    A. Nevertheless    B. Meanwhile    C. Despite    D. Although

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