Answer:
99.24%.
Explanation:
- NaCl reacted with AgNO₃ as in the balanced equation:
<em>NaCl + AgNO₃ → AgCl(↓) + NaNO₃,</em>
1.0 mol of NaCl reacts with 1.0 mol of AgNO₃ to produce 1.0 mol of AgCl and 1.0 mol of NaNO₃.
- We need to calculate the no. of moles of AgCl produced:
no. of moles of AgCl = mass/molar mass = (2.044 g)/(143.32 g/mol) = 0.0143 mol.
- Now, we can calculate the no. of moles of NaCl that can precipitated as AgCl (0.0143 mol), these moles represents the no. of moles of pure NaCl in the sample:
<em>using cross multiplication:</em>
1.0 mol of NaCl produce → 1.0 mol of AgCl, from the stichiometry.
∴ 0.0143 mol of NaCl produce → 0.0143 mol of AgCl.
- Now, we can get the mass of puree NaCl in the sample:
mass of pure NaCl = (no. of moles of pure NaCl)(molar mass of NaCl) = (0.0143 mol)(58.44 g/mol) = 0.8357 g.
∴ The percentage of NaCl in the impure sample = [(mass of pure NaCl)/(mass of the impure sample)] x 100 = [(0.8357 g)/(0.8421 g)] x 100 = 99.24%.
 
        
             
        
        
        
Answer:
142.36 kg
Explanation:
volume of water in the lake = surface area x depth 
= 18.5 x ( 1760 x 3 )² x 39 ft³
= 2.011 x 10¹⁰ ft³
= 2.011 x 10¹⁰ x 28.3168 liter .
= 56.945 x 10¹⁰ liter .
concentration of mercury = .25 x 10⁻⁶ g / liter 
= 25 x 10⁻⁸ g / liter 
= 25 x 10⁻¹¹ kg / liter 
mass of mercury in the water of lake 
= 25 x 10⁻¹¹ x 56.945 x 10¹⁰ kg 
= 142.36 kg . 
 
        
             
        
        
        
Answer:
the answer is A 
Explanation:
it is substrates because ,Enzymes are specialized proteins that catalyze or speed up chemical reactions within cells. The substance upon which an enzyme acts is called a substrate. Substrates are small molecules.
 
        
             
        
        
        
Answer:
The heat produced is -15,1kJ
Explanation:
For the reaction:
2SO₂+O₂ → 2SO₃
The enthalpy of reaction is:
ΔHr = 2ΔHf SO₃ - 2ΔHf SO₂
As ΔHf SO₃ = -395,7kJ and ΔHf SO₂ = -296,8kJ
<em>ΔHr = -197,8kJ</em>
Using n=PV/RT, the moles of reaction are:
 = <em>0,153 moles of reaction</em>
 = <em>0,153 moles of reaction</em>
As 2 moles of reaction produce -197,8kJ of heat, 0,153moles produce:
0,153mol× = <em>-15,1kJ</em>
 = <em>-15,1kJ</em>
<em></em>
I hope it helps!
 
        
             
        
        
        
<h2>Hello!</h2>
The answer is:
The new volume is equal to 206.5 L.
<h2>Why?</h2>
To solve this problem, we need to assume that the pressure is constant, and use the Charle's Law equation, so, solving we have:

We are given:

Then, using the Charle's Law equation, we have:


Hence, we have that the new volume is equal to 206.5 L.
Have a nice day!