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
Answer:
D.) Mg(NO₃)₂
Explanation:
Since magnesium (Mg) is a metal and nitrate (NO₃) is a polyatomic anion, they would combine to form an ionic compound. Magnesium would form the cation Mg²⁺ because it generally has 2 valence electrons. Nitrate always has a -1 charge.
In order for the overall compound to be neutral (have a charge of 0), there must be one Mg²⁺ and two NO₃⁻ ions in the compound (+2 + (-1) + (-1) = 0).
Therefore, the formula for the compound formed is Mg(NO₃)₂.
Answer:
d
Explanation:
sugar molecules are being broken down
Answer:
The correct answer is "The coffee in the jug has more thermal energy than the coffee in the cup".
Explanation:
First I had to look for the problem to know the possible answers.
In this case, the coffee jug has a large amount of coffee at the same temperature. If we analyze that the decanter and the coffee are at the same temperature, we have a homogeneous thermal system. The cup is at room temperature, so by pouring coffee into it, the temperature of the coffee decreases to balance with the temperature of the cup. At this moment, the temperature of the cup-cafe system is lower than the jug-cafe system.
Thermal energy is the part of the internal energy of an equilibrated thermodynamic system that is proportional to its absolute temperature and increases or decreases by energy transfer.
In this way, we can ensure that the thermal energy of the cup-cafe system is lower than that of the jug-cafe system.
Have a nice day!
Extrusive Rocks. Igneous rocks which form by the crystallization of magma at the surface of the Earth are called extrusive rocks. They are characterized by fine-grained textures because their rapid cooling at or near the surface did not provide enough time for large crystals to grow.
