\(C\%=\dfrac{m_{HCl}}{m_{ddHCl}}.100\%\)

\(\Rightarrow m_{HCl}=\dfrac{C\%.m_{ddHCl}}{100}=7,3g\)

\(n_{HCl}=\dfrac{7,3}{36,5}=0,2\left(mol\right)\)

\(Fe+2HCl\rightarrow FeCl_2+H_2\)

DE: 0,1 \(\leftarrow\) 0,2 \(\rightarrow\) 0,1 \(\rightarrow\) 0,1 (mol)

\(m_{FeCl_2}=0,1.127=12,7g\)

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

\(m_{dd}=m_{Fe}+m_{HCl}-m_{H_2}\)

= 5,6 + 100 -0,2 = 105,4 g

\(C\%_{FeCl_2}=\dfrac{m_{FeCl_2}}{m_{dd}}.100\%\approx12,05\%\)

TT: m= 3kg ; h= 6m ;

a, F_k= 15N ; b, F_ms= 4N

=> a,l=?m ; b, H=?

GIAI

a, trong luong cua vat:P=10m= 30N

cong co ich: \(A_1=P.h=30.6=180J\)

vi khong co ma sat => A₁= A₂ = 180J

chieu dai mpn:\(A_2=F_k.l\Rightarrow l=\dfrac{A_2}{F_k}=12m\)

b, cong hao phi:\(A_{hp}=F_{ms}.l=48J\)

cong toan phan khi co ma sat:

\(A_{ms}=A_3-A_1\Rightarrow A_3=A_{ms}+A_1\)=228J

hieu suat mpn:\(H=\dfrac{A_1}{A_3}.100\%=\dfrac{180}{228}.100\%\approx78,95\%\)

 (15⁹   -    15⁸   )    ;   (   7   .   15¹)

= ( 15⁸    .   15    -    15⁸    .     1    )    :   (   7   .   15  )

=15⁸    .   (   15   -   1  )   :  (   7  .  15  )

=(  15⁸   .   14   )   :   (   7   .   15  )

=  (15⁸   .    7   .   2  )   :   (   7   .   15   )    (Bớt cả 2 bên đi cho 7)

Ta được:

=  ( 15⁸ .    2   )   ;   15  

=  (   15⁷     .    15   .  2  )  :    15  (Bớt cả 2 bên đi 15)

Ta được :

=  15⁷    .   2

\(n_{H_2}=\dfrac{112}{22,4}=5\left(mol\right)\)

\(2H_2+O_2\rightarrow2H_2O\)

DE: 5 \(\rightarrow\) 5 (mol)

\(V_{H_2O}=22,4.5=112l\)

a, NaCl

b, Na₂O

c, Na₃PO₄

d, Mg(NO₃)₂

e, Ca₃(PO₄)₂

f, Al₂(SO₄)₃

TT: m= 50kg ; h= 2m ; a,F₁=125N;b,F₂=150N

=> a,s=? ; b,H=? ; c,A_hp=?; d,F_ms=?

GIAI

a, trong luong cua vat:P=10m=50.10=500N

cong co ich: A_ci=P.h=500.2=1000J

vi khong co ma sat nen: A_ci=A_tp1=1000J

chieu dai mpn:A_tp1=F₁.s \(\Rightarrow s=\dfrac{A_{tp1}}{F_1}=\dfrac{1000}{125}=8m\)

b, cong toan phan khi co ma sat:

\(A_{tp2}=F_2.s=150.8=1200J\)

hieu suat cua mpn:\(H=\dfrac{A_{ci}}{A_{tp2}}.100=\dfrac{1000.100}{1200}\approx83,33\%\)

c, cong hao phi:\(A_{hp}=A_{tp2}-A_{ci}=1200-1000=200J\)

d, CACH 1 :do lon luc ma sat:\(A_{hp}=F_{ms}.s\Rightarrow F_{ms}=\dfrac{A_{hp}}{s}=25N\)

CACH 2: do lon luc ma sat:

\(F_{ms}=F_2-F_1=150-125=25N\)

TT: t^o₁=75^oC ; V₂= 8l ; t^o₂=24^oC ; D=1000kg/m³ ; t^o=36^oC ; c=4200 J/kg.k

=> m₁= ? kg

GIAI

khoi luong nuoc trong binh chua:

\(D=\dfrac{m_2}{V_2}\Rightarrow m_2=D.V_2=8kg\)

nhiet luong nuoc thu vao:

\(Q_{thu}=c.m_2.\left(t^o-t^o_2\right)=403200J\)

nhiet luong nuoc toa ra:

\(Q_{toa}=c.m_1.\left(t^o_1-t^o\right)=163800.m_1\)

theo PTCBN: \(Q_{toa}=Q_{thu}\Rightarrow163800.m_1=403200\)

\(\Rightarrow m_1=\dfrac{403200}{163800}=\dfrac{32}{13}\left(kg\right)\)

Sai ben bét.Trả lời cả 3 dòng cơ mà.Gợi ý:Có nhiều hơn 1 thứ.