c) \(m_{d^2}=19,5+200=219,5\left(g\right)\)

\(\rightarrow C\%_{HCl}=\dfrac{0,6\cdot36,5}{219,5}\cdot100\%=9,98\%\)

\(C_{MHCl}=\dfrac{0,6}{0,2}=3M\)

\(n_{Zn}=\dfrac{19,5}{65}=0,3\left(mol\right)\)

\(Zn+2HCl\rightarrow ZnCl_2+H_2\uparrow\)

a) Ta có \(n_{H_2}=n_{Zn}=0,3\left(mol\right)\)

\(\rightarrow\) \(V_{H_2\left(đktc\right)}=0,3\cdot22,4=6,72\left(l\right)\)

b) Ta có \(n_{ZnCl_2}=n_{Zn}=0,3\left(mol\right)\)

\(\rightarrow m_{ZnCl_2}=0,3\cdot136=40,8\left(g\right)\)

c) Ta có \(n_{HCl}=2n_{Zn}=2\cdot0,3=0,6\left(mol\right)\)

\(\rightarrow C_M_{HCl}=\dfrac{0,6}{0,2}=3M\)

Chủ đề 1: Science and technology are essential components of modern society. Science involves the study of the natural world through observation and experimentation, aiming to understand how things work. Technology, on the other hand, applies scientific knowledge to create tools, machines, and systems that improve our lives. Together, they drive innovation, progress, and advancements in various fields such as healthcare, communication, transportation, and more. The continuous development of science and technology has revolutionized the way we live, work, and interact with the world around us, making them indispensable aspects of our daily lives.

\(g_{\left(-1\right)}=\left(-1\right)^2-3\cdot\left(-1\right)+1=1+3+1=5\)

\(g_{\left(0\right)}=0^2-3\cdot0+1=0-0+1=1\)

\(g_{\left(1\right)}=1^2-3\cdot1+1=1-3+1=-1\)

a) \(n_{CaO}=\dfrac{5,6}{56}=0,1\left(mol\right)\)

\(CaO+H_2SO_4\)\(\rightarrow CaSO_4+H_2O\)

b) Ta có \(n_{CaSO_4}=n_{CaO}=0,1\left(mol\right)\)

\(\rightarrow m_{CaSO_4}=0,1\cdot136=13,6\left(g\right)\)

c) Ta có \(n_{H_2SO_4}=n_{CaO}=0,1\left(mol\right)\)

\(\rightarrow m_{H_2SO_4}=0,1\cdot98=9,8\left(g\right)\)

\(-\dfrac{2}{5}x^2y\cdot2xy^3\cdot\dfrac{1}{4}yz\)

\(=\left(-\dfrac{2}{5}\cdot2\cdot\dfrac{1}{4}\right)\cdot\left(x^2\cdot x\right)\cdot\left(y\cdot y^3\cdot y\right)\cdot z\)

\(=-\dfrac{1}{5}x^3y^5z\)

Gọi số sp tổ phải sản xuất theo kế hoạch là: x(sản phẩm) ĐK:x>13

\(\Rightarrow\)Thời gian dự định làm là: \(\dfrac{x}{50}\)(ngày)

    Thời gian thực tế là: \(\dfrac{x+13}{57}\)(ngày)

Theo bài ra ta có pt:

\(\dfrac{x}{50}\)-\(\dfrac{x+13}{57}\)=1

\(\Leftrightarrow\)2850(\(\dfrac{x}{50}\)-\(\dfrac{x+13}{57}\))=2850

\(\Leftrightarrow\)\(57x-50x-650=2850\)

\(\Leftrightarrow\)\(7x=3500\)

\(\Leftrightarrow\)\(x=500\)

Vậy ....

a) 467 x 65 + 35 x 467

=467 x (65+35)

=467 x 100

=46700

b) 678 x 74 + 27 x 678 - 678

=678 x (74+27-1)

=678 x 100

=67800

c) 500 x 34 :100

=17000:100

=170

$+$