Answer:
1.23 M
Explanation:
Molarity of a substance , is the number of moles present in a liter of solution .
M = n / V
M = molarity
V = volume of solution in liter ,
n = moles of solute ,
Moles is denoted by given mass divided by the molecular mass ,
Hence ,
n = w / m
n = moles ,
w = given mass ,
m = molecular mass .
From the question ,
w = given mass of NaCl = 7.2 g
As we know , the molecular mass of NaCl = 58.5 g/mol
Moles is calculated as -
n = w / m = 7.2 g / 58.5 g/mol = 0.123 mol
Molarity is calculated as -
V = 100ml = 0.1 L (since , 1 ml = 1/1000L )
M = n / V = 0.123 mol / 0.1 L = 1.23 M
Zn+2HCl ----> 2ZnCl2 + H2
For 2.50 g of Zn
Mass per mol = 2.50/molar mass of Zn = 2.50/65.38 = 0.0382 g/mol
There are two moles of ZnCl2 and total mass = 2*0.0382*molar mass of ZnCl2 = 2*0.0382*136.286 = 10.42 g
For 2 g of HCl
Mass per mol = 2/2*molar mass of HCl = 2/ (2*36.46) = 0.0274 g/mol
For the two moles of ZnCl2, mass produced = 2*0.0274*136.286 = 7.48 g
It can be noted that 2 g of HCl produced less amount of ZnCl and thus it is the limiting reagent.
Answer:
frequency of light (f) = 1 x 10¹⁵s⁻¹
Explanation:
Given Data:
Wavelength of light λ = 3.0 x10⁻⁷m
Frequency of light: to be calculated
Formula Used to find frequency:
f = V/λ ........................... (1)
where
f is the frequency
V is the velocity
λ is wavelength
Velocity of light = 3 x 10⁸ ms⁻¹
put the values in equation (1)
f = 3 x 10⁸ ms⁻¹ / 3.0 x10⁻⁷m
f = 1 x 10¹⁵s⁻¹
So the frequency of light = 1 x 10¹⁵s⁻¹
Without being given a temperature or amount of solute, it's not as easy to find the level of saturation. If there is excess of solvent in the beaker, the solution is unsaturated. In this case, the solution is clear so there is no indication of excess of solute or solvent. Therefore, the solution is saturated.
