Molality is the number of moles of solute in 1 kg of solvent
number of moles of sucrose - mass of sucrose / molar mass
number of moles of sucrose - 34.2 g / 342.34 g/mol = 0.0999 mol
number of moles in 125 g of water - 0.0999 mol
therefore number of moles in 1000 g - 0.0999 / 125 x 1000 = 0.799 mol/kg
molality of sucrose solution - 0.799 mol/kg
Answer:
Salts and acids are examples of inorganic compounds called <u><em>electrolytes</em></u>.
Explanation:
Electrolytes are the substances which dissociates into ions when dissolved in water and due to this they are able to conduct electric current through them. These compounds in solid form does not conduct electricity due to the absence of free ions.
For example: Sodium chloride , sulfuric acid etc.
Answer:
We have to add 2.30 L of oxygen gas
Explanation:
Step 1: Data given
Initial volume = 4.00 L
Number of moles oxygen gas= 0.864 moles
Temperature = constant
Number of moles of oxygen gas increased to 1.36 moles
Step 2: Calculate new volume
V1/n1 = V2/n2
⇒V1 = the initial volume of the vessel = 4.00 L
⇒n1 = the initial number of moles oxygen gas = 0.864 moles
⇒V2 = the nex volume of the vessel
⇒n2 = the increased number of moles oxygen gas = 1.36 moles
4.00L / 0.864 moles = V2 / 1.36 moles
V2 = 6.30 L
The new volume is 6.30 L
Step 3: Calculate the amount of oxygen gas we have to add
6.30 - 4.00 = 2.30 L
We have to add 2.30 L of oxygen gas
The weight in grams = 7.93 g
Given volume = 2.00 
Given density = 0.242 g/
We need to find the Mass(weight) in grams.
To find the weight in grams we need to keep in mind that the volume and density must use the same volume unit for cancellation. So that the volume units will cancel out, leaving only the mass units.
The unit of given volume is 
and unit of volume in density is , so first we need to change the unit of volume from 
to so that the volume units will cancel out, leaving only the mass units.
1 = 16.39 (given conversion)
units get cancel out leaving the unit.
Mass = Density X Volume.
Density = 0.242 g/ and Volume = 32.78
Mass = 7.93 grams (g)
Answer:
1.59mol/L
Explanation:
Data obtained from the question include:
Mass of MgCl2 = 151g
Volume of water(solvent) = 1L
Now, let us calculate the number of mole of MgCl2. This is illustrated below:
Molarity Mass of MgCl2 = 24 + (2x35.5) = 24 + 71 = 95g/mol
Mass of MgCl2 = 151g
Number of mole of MgCl2 =?
Number of mole = Mass /Molar Mass
Number of mole of MgCl2 = 151/95
Number of mole of MgCl2 = 1.59mole
Now we can calculate the molarity of MgCl2 as follow:
Mole = 1.59mole
Volume = 1L
Molarity =?
Molarity = mole /Volume
Molarity = 1.59/1
Molarity = 1.59mol/L
