Answer:
2 grams
Explanation:
One MOLE of hydrogen atoms contains the same number of atoms as the number of hydrogen molecules in one MOLE of hydrogen molecules, i.e., Avagadros number. However, one mole of hydrogen atoms has a mass of 1 gram while one MOLE of hydrogen molecules has a mass of 2 grams.
Answer:
um you dont need those 2 elements at the end
Answer:
ΔE negative,ΔE positive,ΔE positive
Explanation:
Internal energy change of a system is positive when the system acquires energy from outside and internal energy change is negative when energy is being liberated from the system.
a Sweat evaporates from skin,cooling the skin ΔE is negative as heat energy is liberated through evaporation of sweat.
b A balloon expand against an external pressure ΔE positive because external energy is required to expand the balloon.
c An aqueous chemical reaction mixture is warmed with an external flame ΔE is positive because heat energy is provided by the external flame to warm the aqueous chemical reaction.
Answer:
At lower temperatures the solubility of the KCl decreased and recrystallization occurred
Explanation:
Solubility refers to the amount of solute that dissolves in one litre of water at a particular temperature. Solubility is a property referring to the ability for a given substance, the solute, to dissolve in a solvent. It is measured in terms of the maximum amount of solute dissolved in a solvent at equilibrium. The resulting solution is called a saturated solution.
Solubility is dependent on temperature. This is the reason why we must state the particular temperature at which a given solubility data was collected. Above or below the quoted temperature, the solubility data may no longer be accurate.
Let's return to the question, at elevated temperatures, we can see that the KCl is very soluble in water as evidenced by the clear solution obtained at high temperature. However, as the temperature decreases, the solubility of KCl also decreases accordingly and recrystallization of the solute occurred hence the formation of a cloudy solution and the settling of some solid at the bottom of the flask.
