Answer:an ice cube melting ∆H=+ve
nail polish remover quickly evaporating after it is accidentally spilled on the skin ∆H=-ve
gasoline burning within the cylinder of an automobile engine ∆H=-ve
Explanation:
In an endothermic process, such as the melting of an ice cube, heat is absorbed from the surrounding. The enthalpy change is positive. The evaporation a nail polish and burning of gasoline are exothermic processes which lead to the release of heat to the surrounding. The sign of the enthalpy change in both cases is negative.
The pH of the solution is mathematically given as
PH=7.21
<h3>What would be the pH of the solution?</h3>
Question Parameters:
sodium hydrogen sulfite (NaHSO3) to 50 mL of water.
Generally, the equation for the Chemical Reaction for the acid dissociation is mathematically given as
HSO3- + H2O ---> H3O+ + SO3^2-
Therefore

A-=HA
pH=pKa
Since pKa NaHSO3=7.21
Hence, PH=7.21
For more information on Chemical Reaction
brainly.com/question/11231920
Answer:
13.4g
Explanation:
we know that:
1 mole = 6.02 × 10²³ atoms
make the unknown number of moles = x
x = 7.1 × 10²² atoms
putting them both together:
1 mole = 6.02 × 10²³ atoms
x = 7.1 × 10²² atoms
Cross multiply:
6.02 × 10²³ x = 7.1 × 10²²
divide both sides by 6.02 × 10²³


we now have the number of moles of Al₂CO₃
to calculate the grams (mass):


add up all of the atomic masses of Al₂CO₃ to calculate relative formula mass:
(27 × 2) + 12 + (16 × 3) = 114
the grams (mass) of Al₂CO₃:
