\(1,M_{CO_2}=12+16\cdot2=44\left(g/mol\right)\\ 2,M_{H_2SO_4}=2+32+16\cdot4=98\left(g/mol\right)\\ 3,M_{Cu\left(NO_3\right)_2}=64+\left(14+16\cdot3\right)\cdot2=188\left(g/mol\right)\\ 4,M_{Fe_2\left(SO_4\right)_3}=56\cdot2+\left(32+16\cdot4\right)\cdot3=400\left(g/mol\right)\\ 5,M_{Na_3PO_4}=23\cdot3+31+16\cdot4=164\left(g/mol\right)\)

a)

$n_O = n_{NaOH} = \dfrac{12}{40} = 0,3(mol)$
$m_O = 0,3.16 = 4,8(gam)$

b)

$n_{Fe_2(SO_4)_3} = \dfrac{40}{400} = 0,1(mol)$
$n_O = 12n_{Fe_2(SO_4)_3} = 1,2(mol)$
$m_O = 1,2.16 = 19,2(gam)$

c)

$n_{Na_3PO_4} = \dfrac{8,2}{164} = 0,05(mol)$
$n_O = 4n_{Na_3PO_4} = 0,05.4 = 0,2(mol)$
$m_O = 0,2.16 = 3,2(gam)$

Bài làm

* \(m_{ZnSO4}=n.M=0,25.\left(65+32+16.4\right)=0,25.161=40,25\left(g\right)\)

* \(m_{AlCl3}=n.M=0,2.\left(27+35,5.3\right)=0,2.133,5=26,7\left(g\right)\)

* \(m_{Cu}=n.M=0,3.64=19,2\left(g\right)\)

* \(m_{Ca\left(OH\right)2}=n.M=0,15.\left[40+\left(16+1\right).2\right]=0,15.74=11,1\left(g\right)\)

* \(m_{Fe2\left(SO4\right)3}=n.M=0,35.\left[56+\left(32+16.4\right).3\right]=0,35.344=120,4\left(g\right)\)

# Học tốt #

a) \(n_{Fe}=\dfrac{14}{56}=0,25\left(mol\right)\)

\(n_{CaCO_3}=\dfrac{25}{100}=0,25\left(mol\right)\)

\(n_{NaOH}=\dfrac{4}{40}=0,1\left(mol\right)\)

\(n_{...}=\dfrac{1,5.10^{23}}{6.10^{23}}=0,25\left(mol\right)\)

b) 

\(m_{ZnSO_4}=0,25.161=40,25\left(g\right)\)

\(m_{AlCl_3}=0,2.133,5=26,7\left(g\right)\)

\(m_{Cu}=0,3.64=19,2\left(g\right)\)

\(m_{Fe_2\left(SO_4\right)_3}=0,35.400=140\left(g\right)\)

d) \(V_{CO_2}=0,2.22,4=4,48\left(l\right)\)

\(V_{Cl_2}=0,15.22,4=3,36\left(l\right)\)

\(V_{SO_2}=0,3.22,4=6,72\left(l\right)\)

Câu a.

\(M_{Ca\left(NO_3\right)_2}=164\)g/mol

\(m_{Ca\left(NO_3\right)_2}=0,3\cdot164=49,2g\)

\(\%Ca=\dfrac{40}{164}\cdot100\%=24,39\%\)

\(m_{Ca}=\%Ca\cdot49,2=12g\)

\(\%N=\dfrac{14\cdot2}{164}\cdot100\%=17,07\%\)

\(m_N=\%N\cdot49,2=8,4g\)

\(m_O=49,2-12-8,4=28,8g\)

Các câu sau em làm tương tự nhé!

a)\(n_{Ca\left(NO_3\right)_2}=0,3mol\)

   \(n_{Ca}=n_{Ca\left(NO_3\right)_2}=0,3mol\)

   \(m_{Ca}=0,3\cdot40=12g\)

   \(n_N=2n_{Ca\left(NO_3\right)_2}=2\cdot0,3=0,6mol\)

   \(m_N=0,6\cdot14=8,4g\)

   \(n_O=6n_{Ca\left(NO_3\right)_2}=6\cdot0,3=1,8mol\)

   \(m_O=1,8\cdot16=28,8g\)

b)\(n_O=\dfrac{9,6}{16}=0,6mol\)

   Mà \(n_O=12n_{Fe_2\left(SO_4\right)_3}\Rightarrow n_{Fe_2\left(SO_4\right)_3}=\dfrac{0,6}{12}=0,05mol\)

   \(\Rightarrow m=20g\)

c)\(n_{CuSO_4}=\dfrac{3,2}{160}=0,02mol\)

   \(n_O=4n_{CuSO_4}=0,08mol=n_{H_2}\)

   \(V_{H_2}=0,08\cdot22,4=1,792l\)

a) 

\(n_{Fe}=\dfrac{14}{56}=0,25\left(mol\right)\)

\(n_{Ca}=\dfrac{20}{40}=0,5\left(mol\right)\)

\(n_{CaCO_3}=\dfrac{25}{100}=0,25\left(mol\right)\)

\(n_{NaOH}=\dfrac{4}{40}=0,1\left(mol\right)\)

\(n_{H_2O}=\dfrac{1,5.10^{23}}{6.10^{23}}=0,25\left(mol\right)\)

b) 

\(m_{ZnSO_4}=0,25.161=40,25\left(g\right)\)

\(m_{AlCl_3}=0,2.133,5=26,7\left(g\right)\)

\(m_{Cu}=0,3.64=19,2\left(g\right)\)

\(m_{Fe_2\left(SO_4\right)_3}=0,35.400=140\left(g\right)\)

c)

\(V_{CO_2}=0,2.22,4=4,48\left(l\right)\)

\(V_{Cl_2}=0,15.22,4=3,36\left(l\right)\)

\(V_{SO_2}=0,3.22,4=6,72\left(l\right)\)

\(V_{CH_4}=0,5.22,4=11,2\left(l\right)\)

a: \(n_{Fe}=\dfrac{14}{56}=0.25\left(mol\right)\)

\(n_{Ca}=\dfrac{20}{40}=0.5\left(mol\right)\)

\(1:2:1:1:1\)

\(1:1:2\)

\(1:3:1:3\)

\(1:1:1:1\)

\(1:2:1:2\)

\(2:1:1:1\)

\(1:4:1:1:2\)

\(1:3:2\)

Theo thứ tự các chất trong phương trình:

1) 1 : 2 : 1 : 1 : 1

2) 1 : 1 : 2

3) 1 : 3 : 1 : 3

4) 1 : 1 : 1 : 1

5) 1 : 2 : 1 : 2

6) 2 : 1 : 1 : 1

7) 1 : 4 : 1 : 1 : 2

8) 1 : 3 : 2

\(m_{Fe_2\left(SO_4\right)_3}=0.25.400=100\left(g\right)\)

m Fe₂(SO₄)₃ = n . M = 0.25 . (56.2 + (32 + 16.4).3) = 100 (g)