Answer:
We will expect 4 moles of MgO to be formed (option b).
Explanation:
Step 1: The balanced equation
2Mg + O2 → 2MgO
Step 2: Data given
Number of moles of Magnesium = 4 moles
Oxygen = in excess → this means Magnesium is the limiting reactant
Magnesium will completely be consumed ( 4 moles). There will remain 0 moles.
For 2 moles of magnesium consumed, we need 1 mole of oxygen to produce 2 moles of MgO.
For 4 moles of magnesium, we need 4/2 = 2 moles of oxygen.
For 4 moles of magnesium, we will produce 4/1 = 4 moles of MgO
We will expect 4 moles of MgO to be formed (option b).
Answer:
Group of highly-reactive chemical elements. The alkali metals are a group (column) in the periodic table consisting of the chemical elements lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr).
Hi :)
The bottom number tells you how many protons you have in the nucleus of this element.
In Krypton-84, this means that you have 84 nucleons, where 36 of these are protons, and the remaining 48 are neutrons.
Hope this helps :)
It has to be 120g because each and every chemical equation has to satisfy the law of conservation of mass, ie sum of mass of products is always equal to the sum of masses of reactants. If reactants=120g, then products=120g
You must add 7.5 pt of the 30 % sugar to the 5 % sugar to get a 20 % solution.
You can use a modified dilution formula to calculate the volume of 30 % sugar.
<em>V</em>_1×<em>C</em>_1 + <em>V</em>_2×<em>C</em>_2 = <em>V</em>_3×<em>C</em>_3
Let the volume of 30 % sugar = <em>x</em> pt. Then the volume of the final 20 % sugar = (5 + <em>x</em> ) pt
(<em>x</em> pt×30 % sugar) + (5 pt×5 % sugar) = (<em>x</em> + 5) pt × 20 % sugar
30<em>x</em> + 25 = 20x + 100
10<em>x</em> = 75
<em>x</em> = 75/10 = 7.5
