Answer:
By the time the Vesuvius eruption sputtered to an end the next day, Pompeii was buried under millions of tons of volcanic ash. About 2,000 Pompeiians were dead, but the eruption killed as many as 16,000 people overall. By
the time the Vesuvius eruption sputtered to an end the next day, Pompeii was buried under millions of tons of volcanic ash. About 2,000 Pompeiians were dead, but the eruption killed as many as 16,000 people overall.
Explanation:
The structure of this oligopeptide is attached:
It consists of arginine - alanine - phenylalanine and leucine
From the picture we can see that N terminus charge is +1
Also Arginine is considered as basic amino acid with charge +1
C terminus charge is -1
At pH = 8, the whose pKa are less than pH will be deprotonated and the net charge will be +1
So the net charge of this oligopeptide is +1 at pH = 8
Answer:
Explanation:
1. New substances such as carbondioxide and water is formed.
2. There is evolution of gas bubbles. Gases are released.
3. There is either the absorption of energy or release of energy in form of light and energy.
4. The reaction is irreversible i.e it cannot be reversed, it is permanent once the reaction take place.
5. There is a change in both odor and smell.
A chemical change is a change where new substances are formed due to changes in the properties.
Answer:
Explanation:
Given parameters:
Mass of aluminium oxide = 3.87g
Mass of water = 5.67g
Unknown:
Limiting reactant = ?
Solution:
The limiting reactant is the reactant in short supply in a chemical reaction. We need to first write the chemical equation and convert the masses given to the number of moles.
Using the number of moles, we can ascertain the limiting reactants;
Al₂O₃ + 3H₂O → 2Al(OH)₃
Number of moles;
Number of moles = 
molar mass of Al₂O₃ = (2x27) + 3(16) = 102g/mole
number of moles =
= 0.04mole
molar mass of H₂O = 2(1) + 16 = 18g/mole
number of moles =
= 0.32mole
From the reaction equation;
1 mole of Al₂O₃ reacted with 3 moles of H₂O
0.04 mole of Al₂O₃ will react with 3 x 0.04 mole = 0.12 mole of H₂O
But we were given 0.32 mole of H₂O and this is in excess of amount required.
This shows that Al₂O₃ is the limiting reactant