The empirical formula : MnO₂.
<h3>Further explanation</h3>
Given
632mg of manganese(Mn) = 0.632 g
368mg of oxygen(O) = 0.368 g
M Mn = 55
M O = 16
Required
The empirical formula
Solution
You didn't include the pictures, but the steps for finding the empirical formula are generally the same
- Find mol(mass : atomic mass)
Mn : 0.632 : 55 = 0.0115
O : 0.368 : 16 =0.023
- Divide by the smallest mol(Mn=0.0115)
Mn : O =
The empirical formula : MnO₂
First find the number of moles of sulfur using dimensional analysis with avogadro’s number as the conversion factor. 4.2*10^24 atoms * (1 mol/6.022*10^23 atoms) = 7.0 mol sulfur. The molar mass of sulfur is 32.06 g/mol, which is found on the periodic table as sulfur’s (S) atomic weight. Use dimensional analysis again with the molar mass of sulfur as the conversion factor. 7.0 mol * 32.06 g/mol = 224.42 g sulfur. Since the problems gives us two significant figures, round the mass of sulfur to 220 grams, or 2.2 * 10^2 g.
Answer: products; reactants
Explanation: as the endothermic reactions are tye one which absorbs energy
Answer:
-65.897°C.
Explanation:
- Adding solute to water causes depression of the boiling point.
- The depression in freezing point (ΔTf) can be calculated using the relation: <em>ΔTf = Kf.m,</em>
where, ΔTf is the depression in freezing point of chloroform solution.
Kf is the molal depression constant of chloroform (Kf = 4.70°C.kg/mol).
m is the molality of the solution (m = 0.51 m).
∴ ΔTf = Kf.m = (4.70°C.kg/mol)(0.51 m) = 2.397°C.
∴ The freezing point of the solution = (freezing point of chloroform) - ΔTf = (-63.5°C) - (2.397°C) = -65.897°C.
The answer is (3) Mg because Ca and Mg are in the same group (group 2).
Hope this helps~
