đề hỏi gì??

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Lớp 7 , Hóa học =)))))))))))))))

Lớp 7 có hóa à????

lớp 7 có hóa ???              

n_Fe = 16.8/56 = 0.3 (mol) 

3Fe + 2O₂ -to-> Fe₃O₄ 

0.3......0.2...........0.1

VO2 = 0.2*22.4 = 4.48 (l) 

mFe3O4 = 0.1*232 = 23.2 (g) 

2KClO3-to>2KCl+3O2

0,2---------------------0,3

4P+5O2-to->2P2O5

       --0,3-------0,12 mol

n KClO3=\(\dfrac{24,5}{122,5}=0,2mol\)

=>VO2=0,3.22,4=6,72l

=>m P2O5=0,12.142=17,04g

=>Vkk=6.72.5=33,6l

nKClO3 = 24,5 : 122,5 = 0,2 (mol) 
pthh : 2KClO3 -t--> 2KCl +3 O2 
           0,2---------------------> 0,3(MOL)
VO2 = 0,3 .22,4 = 6,72 (L)
 pthh : 4P+5O2-t--> 2P2O 5 
                  0,3--->     0,12 (mol) 
=> mP2O5 = 0,12 .  142 = 17,04 (g) 
ta co : Vkk = VO2:21% = 6,72 : 21% 32 (l) 
 

\(PTHH:4P+5O_2-^{t^o}>2P_2O_5\)

áp dụng ĐLBTKL ta có

\(m_P+m_{O_2}=m_{P_2O_5}\\ =>m_{O_2}=m_{P_2O_5}-m_P\\ =>m_{O_2}=7,1-3,1\\ =>m_{O_2}=4\left(g\right)\)

a) $\rm 4P + 5O_2 \xrightarrow{t^o} 2P_2O_5$
b) Áp dụng ĐLBTKL:
$\rm m_P + m_{O_2} = m_{P_2O_5}$
$\rm \Rightarrow m_{O_2} = m_{P_2O_5} - m_P = 7,1 - 3,1 = 4 (g)$

\(a,PTHH:4P+5O_2\xrightarrow{t^o}2P_2O_5\\ b,m_{P}+m_{O_2}=m_{P_2O_5}\\ c,m_{O_2}=m_{P_2O_5}-m_{P}=28,4-12,4=16(g)\)

\(1,PTHH:CaCO_3\underrightarrow{t^o}CaO+CO_2\)

\(áp,dụng.dlbtkl,ta.có:\)

\(m_{CaCO_3}=m_{CaO}+m_{CO_2}\\ m_{CO_2}=m_{CaCO_3}-m_{CaO}=5-2,8=2,2\left(g\right)\)

\(2,a,pthh:4P+5O_2\underrightarrow{t^o}P_2O_5\)

\(n_P=\dfrac{m}{M}=\dfrac{12.4}{31}=0,4\left(mol\right)\)

\(b,theo.pthh\Rightarrow n_{O_2}=\dfrac{5}{4}n_P=\dfrac{5}{4}.0,4=0,5\left(mol\right)\\ \Rightarrow V_{O_2}=n.22,4=0,5.22,4=11,2\left(l\right)\\ m_{O_2}=n.M=0,5.32=16\left(g\right)\)

1. Áp dụng ĐLBTKL, ta có:

\(m_{CaCO_3}=m_{CaO}+m_{CO_2}\)

\(\Leftrightarrow5=2,8+m_{CO_2}\)

\(\Leftrightarrow m_{CO_2}=5-2,8=2,2\left(g\right)\)

2. Ta có: \(n_P=\dfrac{12,4}{31}=0,4\left(mol\right)\)

a. \(PTHH:4P+5O_2\overset{t^o}{--->}2P_2O_5\)

b. Theo PT: \(n_{O_2}=\dfrac{5}{4}.n_P=\dfrac{5}{4}.0,4=0,5\left(mol\right)\)

Theo PT: \(n_{P_2O_5}=\dfrac{1}{2}.n_P=\dfrac{1}{2}.0,4=0,2\left(mol\right)\)

\(\Rightarrow\left\{{}\begin{matrix}V_{O_2}=0,5.22,4=11,2\left(lít\right)\\m_{P_2O_5}=0,2.142=28,4\left(g\right)\end{matrix}\right.\)

ấn F để cầu tôi trên 5 hóa