GIÚP MÌNH CÂU 29 --> CÂU 40
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20 tháng 2 2023
29:
uses crt;
var n,i,j,kt:integer;
a:array[1..100]of integer;
begin
clrscr;
readln(n);
for i:=1 to n do
readln(a[i]);
for i:=1 to n do
if a[i]>1 then
begin
kt:=0;
for j:=2 to trunc(sqrt(a[i])) do
if a[i] mod j=0 then kt:=1;
if kt=0 then write(a[i]:4);
end;
readln;
end.
NV
Nguyễn Việt Lâm
Giáo viên
10 tháng 5 2021
\(f'\left(x\right)=\dfrac{-3}{\left(x-1\right)^2}\) ; \(f''\left(x\right)=\dfrac{6}{\left(x-1\right)^3}\)
\(f'\left(x\right)+f''\left(x\right)=0\Leftrightarrow\dfrac{-3}{\left(x-1\right)^2}+\dfrac{6}{\left(x-1\right)^3}=0\) (\(x\ne1\))
\(\Leftrightarrow-3\left(x-1\right)+6=0\Rightarrow x=3\)
H
17 tháng 4 2023
28)
$n_{CO_2} = \dfrac{6,72}{22,4} = 0,3(mol)$
$n_{H_2O} = \dfrac{9,9}{18} = 0,55(mol)$
Ta thấy : $n_{H_2O} > n_{CO_2} \to$ Ancol no
$\Rightarrow n_{O\ trong\ X} = n_{OH} = n_{H_2O} - n_{CO_2} = 0,25(mol)$
$\Rightarrow m_X = m_C + m_H + m_O = 0,3.12 + 0,55.2 + 0,25.16 = 8,7(gam)$
Khi ete hóa : $n_{H_2O} = \dfrac{1}{2}n_{OH} = 0,125(mol)$
$\Rightarrow m_{ete} = m_X - m_{H_2O} = 8,7 - 0,125.18 = 6,45(gam)$
Đáp án A
29)
$n_{CO_2} = 0,3(mol) ; n_{O_2} = 0,35(mol)$
Bảo toàn C :
$n_C = n_{CO_2} = 0,3(mol)$
Số nguyên tử C = $\dfrac{n_C}{n_X} = \dfrac{0,3}{0,1} = 3$
Loại : đáp án A
X là ancol no $\to n_{H_2O} - n_{CO_2} = n_X \Rightarrow n_{H_2O} = 0,4(mol)$
$\Rightarrow n_H = 2n_{H_2O} = 0,8(mol)$
Số nguyên tử H $= \dfrac{n_H}{n_X} = 8$
Bảo toàn nguyên tố C :
$n_{OH} + 2n_{O_2} = 2n_{CO_2} + n_{H_2O} \to n_{OH} = 0,2$
Số nhóm $OH = \dfrac{n_{OH}}{n_X} = 2$
Vậy CT của X là $C_3H_6(OH)_2$
DT
Đỗ Thanh Hải
CTVVIP
13 tháng 4 2021
2 The man about whom we are talking taught us English
3 The matter to which you should pay attention is of great important
4 The woman to whom you gave place on the bus lives next door to me
DT
Đỗ Thanh Hải
CTVVIP
13 tháng 4 2021
5 The school at which we are studying is too large
6 THe girl with whom I went on holiday is so cute
7 The city in which my grandmother live seems to be quiet
8 It is the shop in which my sister works
9 They are the interesting books for which I have been looking
10 The picnic to which I went yesterday morning was really exciting
14 The film The eigh-year-old bride about which Mai talked is very too long
15 Ba Be National park about which my friends talking is very beautiful
16 The college at which we used to study was large with a large ground
17 Mrs Hoa, about whom the students are talking, is very lovely and gentle
18 The villa in which they lived is not only beautiful but also very modern
29 better
30 consumption
31 qualified
32 environmentalists
33 destroyed
34 abruptedly
VIII
35 Tet is the best time when family member from all over the country come back home
36 The parents felt happy when they were informed about their children's examination results
IX
1 Because of performing excellently at AFC tournament, everybody admired U23 VN
2 I have not heard that news from my close friend for 2 days
3 Robinson Crusoe novel, which was bought by my father last week, is interesting
4 Our teacher advised us to wear medical face mask when going out
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