First, we have to to whatever is in the parentheses:
(26 + 2)/7
(28)/7
Now solve:
28/7
4
Hope this helps!
Answer:
Mass = 76.176 g
Explanation:
Given data:
Mass of lead(II) chloride produced = 62.9 g
Mass of lead(II) nitrate used = ?
Solution:
Chemical equation:
Pb(NO₃)₂ + 2HCl → PbCl₂ + 2HNO₃
Number of moles of lead(II) chloride:
Number of moles = mass/molar mass
Number of moles = 62.9 g/ 278.1 g/mol
Number of moles = 0.23 mol
Now we will compare the moles of lead(II) chloride with Pb(NO₃)₂ from balance chemical equation:
PbCl₂ : Pb(NO₃)₂
1 : 1
0.23 : 0.23
Mass of Pb(NO₃)₂:
Mass = number of moles × molar mass
Mass = 0.23 mol × 331.2 g/mol
Mass = 76.176 g
<h3>
Answer:</h3>
43.27 g Mg
<h3>
Explanation:</h3>
The balanced equation for the reaction between magnesium metal and hydrochloric acid is;
Mg(s) + 2HCl(aq) → MgCl₂(aq) + H₂(g)
From the equation;
1 mole of magnesium reacts with 2 moles of HCl
We are given;
3.56 moles of Mg and 3.56 moles of HCl
Using the mole ratio;
3.56 moles of Mg would react with 7.12 moles of HCl, and
3.56 moles of HCl would react with 1.78 moles of Mg
Therefore;
The amount of magnesium was in excess;
Moles of Mg left = 3.56 moles - 1.78 moles
= 1.78 moles
But; 1 mole of Mg = 24.305 g/mol
Therefore;
Mass of magnesium left = 1.78 moles × 24.305 g/mol
= 43.2629 g
= 43.27 g
Thus, the mass of magnesium that remained after the reaction is 43.27 g
Answer : The final volume at STP is, 1000 L
Explanation :
According to the Boyle's, law, the pressure of the gas is inversely proportional to the volume of gas at constant temperature and moles of gas.
or,
where,
= initial pressure = 1520 mmHg = 2 atm (1 atm = 760 mmHg)
= final pressure at STP = 1 atm
= initial volume = 500.0 L
= final volume at STP = ?
Now put all the given values in the above formula, we get:
Therefore, the final volume at STP is, 1000 L
Answer:
a limiting rule or circumstance; a restriction.
Example:
Also knowing her limitations, she'd declined the invitation to join them
