Answer:
K₂CO₃
Explanation:
Given parameters:
Number of moles of K = 0.104mol
Number of moles of C = 0.052mol
Number of moles of O = 0.156mol
Method
From the given parameters, to calculate the empirical formula of the elements K, C and O, we reduce the given moles to the simplest fraction.
Empirical formula is the simplest formula of a compound and it differs from the molecular formula which is the actual formula of a compound.
- Divide the given moles through by the smallest which is C, 0.052mol.
- Then approximate values obtained to the nearest whole number of multiply by a factor to give a whole number ratio.
- This is the empirical formula
Solution
Elements K C O
Number of moles 0.104 0.052 0.156
Dividing by the
smallest 0.104/0.052 0.052/0.052 0.156/0.052
2 1 3
The empirical formula is K₂CO₃
Answer:
1.73 M
Explanation:
We must first obtain the concentration of the concentrated acid from the formula;
Co= 10pd/M
Where
Co= concentration of concentrated acid = (the unknown)
p= percentage concentration of concentrated acid= 37.3%
d= density of concentrated acid = 1.19 g/ml
M= Molar mass of the anhydrous acid
Molar mass of anhydrous HCl= 1 +35.5= 36.5 gmol-1
Substituting values;
Co= 10 × 37.3 × 1.19/36.5
Co= 443.87/36.6
Co= 12.16 M
We can now use the dilution formula
CoVo= CdVd
Where;
Co= concentration of concentrated acid= 12.16 M
Vo= volume of concentrated acid = 35.5 ml
Cd= concentration of dilute acid =(the unknown)
Vd= volume of dilute acid = 250ml
Substituting values and making Cd the subject of the formula;
Cd= CoVo/Vd
Cd= 12.16 × 35.5/250
Cd= 1.73 M
Answer:
In this SI units system, there are seven SI base units and three supplementary units. The base SI units are metre, kilogram, second, kelvin, ampere, candela and the mole and the three supplementary SI units are radian, steradian and becquerel. All other SI units can be derived from these base units.
Explanation:
Two 1+ ions are needed in order to balance one 2- ion.
