Explanation:
Given
The enthalpy of formation of RbF (s) is –557.7kJ/mol
The standard enthalpy of formation of RbF (aq, 1 m) is –583.8 kJ/mol
The enthalpy of solution of RbF = Enthalpy of RbF (aq) - Enthalpy of formation of RbF (s)
= -583.8 - (-557.7) kJ/mol
= -26.1 kJ/mol
The enthalpy is negative which means that the temperature will rise when RbF is dissolved.
Given:
Mixture of vitamin water = 75% pure water & 25% concentrated vitamin drink.
To find:
Quantity of water to be added to 16 gallons of concentrated vitamin drink to prepare a tank of vitamin water.
Solution:
Let total amount of mixture be x.
25% of x = 16 gallons (from given information)
When 25% of x is 16 gallons, the remaining 75% of x will be calculated as below:
(16/25)*75 = 48
Answer: 75% of x = 48 gallons. This means 48 gallons pure water is required to be added to mixture to prepare a tank of vitamin water.
Answer : The mass of NaCl needed would be, 86.1 grams.
Explanation :
Formula used for Elevation in boiling point :
or,
where,
= change in temperature =
= boiling point constant =
m = molality
i = Van't Hoff factor = 2 (for NaCl electrolyte)
= mass of solute (NaCl) = ?
= mass of solvent (water) = 1001 g
= molar mass of solute (NaCl) = 58.5 g/mol
Now put all the given values in the above formula, we get:
Therefore, the mass of NaCl needed would be, 86.1 grams.
Answer:
The air would still be too thin to breathe. The lack of atmosphere would chill the Earth's surface. Organisms that need air to breathe would die.
Explanation:
Hope it helped!
Answer:
science is valued by the society because the application of scientific knowledge helps to satisfy many basic human needs and improve living standards
Explanation:
Finding a cure for cancer and a clean form of energy are just two typical examples