Answer:
E - Be and O
A - Mg and N
E - Li and Br
F - Ba and Cl
B - Rb and O
Explanation:
Be and O
Be is a metal that loses 2 e⁻ to form Be²⁺ and O is a nonmetal that gains 2 e⁻ to form O²⁻. For the ionic compound to be neutral, it must have the form BeO (E-MX).
Mg and N
Mg is a metal that loses 2 e⁻ to form Mg²⁺ and N is a nonmetal that gains 3 e⁻ to form O³⁻. For the ionic compound to be neutral, it must have the form Mg₃N₂ (A-M₃X₂).
Li and Br
Li is a metal that loses 1 e⁻ to form Li⁺ and Br is a nonmetal that gains 1 e⁻ to form Br⁻. For the ionic compound to be neutral, it must have the form LiBr (E-MX).
Ba and Cl
Ba is a metal that loses 2 e⁻ to form Ba²⁺ and Cl is a nonmetal that gains 1 e⁻ to form Cl⁻. For the ionic compound to be neutral, it must have the form BaCl₂ (F-MX₂).
Rb and O
Rb is a metal that loses 1 e⁻ to form Rb⁺ and O is a nonmetal that gains 2 e⁻ to form O²⁻. For the ionic compound to be neutral, it must have the form Rb₂O (B-M₂X).
Answer is: the molar mass od sodium carbonate (Na₂CO₃) is 106.0 g/mol.
M(Na₂CO₃) = 2 · Ar(Na) + Ar(C) + 3 · Ar(O).
M(Na₂CO₃) = 2 · 23 + 12 + 3 · 16 · g/mol.
M(Na₂CO₃) = 46 + 12 + 48 · g/mol.
M(Na₂CO₃) = 106 g/mol; molar mass of sodium carbonate.
Ar is relative atomic mass (the ratio of the average mass of atoms of a chemical element to one unified atomic mass unit) of an element.
Answer:
The standard cell potential of the reaction is 0.78 Volts.
Explanation:
Reduction at cathode :
Reduction potential of 
to Cu=
Oxidation at anode:
Reduction potential of 
to Fe=
To calculate the 
of the reaction, we use the equation:
Putting values in above equation, we get:
The standard cell potential of the reaction is 0.78 Volts.
Answer:
2.5
Explanation:
The given costs for the purchase and delivery of the cupcakes are;
The cost of 10 cupcakes and the delivery fee = $30
The cost of 25 cupcakes and the delivery fee = $67.50
Let 'c' represent the fixed cost of delivery of the cup cakes, and let 'x' represent the cost of each cup cake, we have;
30 = 10·x + c...(1)
67.50 = 25·x + c...(2)
Subtracting equation (1) from equation (2) gives;
67.50 - 30 = 37.50 = 25·x - 10·x + c - c = 15·x
∴ x = 37.50/15 = 2.5
The cost of each cupcake, x = 2.5
(∴ The delivery fee = 30 - 10 × 2.5 = 5)
The cost of each cupcake is 2.5.
