Answer:
Chemical Changes in Burning Candle: When you light the candle, the wax present near the wick will melt. Wick absorbs the liquid wax. The liquid wax vaporizes due the heat produced by the flame. This wax vapor near to flame burns and gives new substances like Carbon Dioxide, Carbon soot, water vapours, heat and light.
Explanation:
Answer:
Mixing of salt is physical change.
Explanation:
Mixing of salt is physical change because no chemical reaction occur between them. Sand is non polar while salt is polar.
Physical Change:
The changes that occur only due to change in shape or form but their chemical or internal composition remain unchanged.
These changes were reversible.
They have same chemical property.
These changes can be observed with naked eye.
Chemical change:
The changes, that occur due to change in the composition of a substance and result in a different compound is known as chemical change.
These changes are irreversible
These changes occur due to chemical reactions
These may not be observed with naked eye
Answer:
C) 0.800 mol
Explanation:
In order to <u>convert from moles of Al₂O₃ into moles of Al</u>, we'll need to use<em> the stoichiometric coefficients</em>, using a conversion factor that has Al₂O₃ moles in the denominator and Al moles in the numerator:
- 0.400 mol Al₂O₃ *
= 0.800 mol Al
So the correct answer is option C).
Answer: when concentrations of acid and base are same, pH = pKa
PH = 12.38 pOH = 1.62
Explanation: pKa= -log(Ka)= 12.38. PH + pOH = 14.00
