Percent strength (% w/w) of a solution is defined as the amount of solute present in 100 g of the solution.
Given data:
Mass of the solute, potassium chloride = 62.5 g
Volume of water (solution) = 187.5 ml
We know that the density of water = 1 g/ml
Therefore, the mass corresponding to the given volume of water
= 187.5 ml * 1 g/1 ml = 187.5 g
We have a solution of 62.5 g of potassium chloride in 187.5 g water
Therefore, amount of solute in 100 g of water= 62.5 * 100/187.5 = 33.33
The percentage strength = 33.33 %
Answer:
5 loaves of bread, 5g of yeast
Explanation:
During a chemical change, a new kind of matter is formed. Examples are combustion, rusting of iron, precipitation and souring of milk.
Here are some of the properties of chemical change:
- They are not easily reversible
- It leads to the production of new kinds of matter.
- It involves change in mass.
- It requires a considerable amount of energy.
Learn more:
Chemical change brainly.com/question/9388643
#learnwithBrainly
Answer:
The system gains 126100 J
Explanation:
The heat can be calculated by the equation:
Q = nxCxΔT, where Q is the heat, C is the heat capacity,n is the number of moles and ΔT is the variation of temperature (final - initial). The number of moles is the mass divided by the molar mass, so:
n = 250/4 = 62.5 mol.
The system must be in thermal equilibrium with the surroundings, so if the temperature of the surroundings decreased 97 K, the temperature of the system increased by 97 K, so ΔT = 97 K
Q = 62.5x20.8x97
Q = 126100 J
