When the concentration is expressed in percentage, that is the ratio of the mass of solute to the mass of the total solution. Since the given amount of solution is in terms of volume, let's use the density to find the mass. Note that 1 mL is just equal to 1 cm³.
45 mL * 1.19 g/cm³ = 53.55 g HCl solution
Mass Percent = Mass Solute/Mass Solution * 100
37.21% = Mass Solute/53.55 g * 100
Mass Solute = 19.93 g HCl
Answer:
Period 4
Explanation:
On the modern periodic table, potassium and calcium lie in the fourth period, Period 4.
Elements are arranged on the periodic table based on their atomic numbers or number of protons.
- Period 4 is made up of elements that have 4 energy levels.
- Potassium and calcium have 4 energy levels and belongs to the fourth period.
Answer:
80g/mol is the molar mass of the metal
Explanation:
A divalent metal M reacts with HCl as follows:
M + 2HCl → MCl₂ + H₂
The excess of HCl is titrated with NaOH. Thus, we can solve the moles of HCl that reacts with the metal and the moles of the metal. As the atomic weight is the ratio between the mass and moles of the atom:
<em>Moles NaOH:</em>
0.0546L * (0.22mol / L) = 0.0120 moles NaOH = Moles HCl in excess
<em>For NaOH and HCl solutions, Normality is the same than molarity.</em>
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<em>Moles HCl added:</em>
0.100L * (1.28mol / L) = 0.128 moles HCl * (50mL / 200mL) = 0.032 moles
<em>Moles HCl in that react:</em>
0.032 moles - 0.012 moles = 0.020 moles HCl
<em>Moles M:</em>
0.020 moles HCl * (1mol M / 2 mol HCl) = 0.010 moles M
<em>Molar mass M:</em>
0.8g / 0.010mol =
<h3>80g/mol is the molar mass of the metal</h3>
I believe that would be C6H6, Benzene.
Hope it helps!
