6.8x10^5? Scientific notation
18 electrons. With a -2 charge, that means it gains two electrons.
Answer:
1. Options A and B
2. Options B and C
3.. B. Net ∆G = -16.7 KJ/mol; C. Net ∆G = -14.2 KJ/mol
Explanation:
1. The spontaneity of a chemical reaction depends on its standard free energy change, ∆G. If ∆G is negative, the reaction is favourable, but when it is positive, the reaction is unfavorable.
Therefore, since reaction A and B have ∆G to be positive, they are unfavorable
2. Coupling an unfavorable reaction to a favourable reaction can help the reaction to proceed in the forward direction as long as the net free energy change is negative.
Coupling reaction A and C, as well as reaction B and C will make the reactions to become favourable as net ∆G is negative in both instances.
3. A and C: net ∆G = 13.8 - 30.5 = -16.7 KJ/mol
B and C: net ∆G = 16.3- 30.5 = -14.2 KJ/mol
Empirical Formulae for;
Compound 1- K5 Mn5 O16
Compound 2- Na2 Cr2 O7
Compound 3- C3 H4 O4
Compound 4- C3 H3 O1
Explanation:
Step 1; as all the element percentages are given in percent assume the total mass of the compound is 100g and take each percentage as grams i.e., 27.5% of K as 27.5 g of K and so on.
Step 2; convert the mass of each element into their mole values by dividing available mass by molar masses.
Molar masses of required elements are as follows; K=39, Mn=55, O=16 C=12, H=1, Na=23, Cr=52.
Step 3; Divide all the values by the smallest mole value. I.e. for compound 1 after dividing the masses by molar masses we get 0.705, 0.681, and 2.187 for elements K, Mn, O respectively. Divide all three values with the least value which is 0.681 and write these values down.
Step 4; Convert all the numbers available into whole numbers by multiplying with suitable values. i.e. 3 if values are 0.33, 2 if values are 0.5 etc.
Step 5; Assign these values to corresponding elements and you will get the above empirical formula.
<u>Answer:</u>
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<u>Explanation:</u>
Balancing is making the number of atoms of each element same on both the sides (reactant and product side).
To find the number of atoms of each element we multiply coefficient 
subscript
For example 
contains
5 × 1 = 5 ,Ca atoms and
5 × 2 = 10, Cl atoms
If there is a bracket in the chemical formula
For example 
we multiply coefficient × subscript × number outside the bracket to find the number of atoms
(Please note: 3 is the coefficient, and if there is no number given then 1 will be the coefficient )
So
3 × 3 = 9 , Ca atoms
3 × 1 × 2 = 6, P atoms
3 × 4 × 2 = 24, O atoms are present.
So
Let us balance the equation given
(balanced equation)
<u>Reactant side </u> <u>Elements</u> <u>Product side
</u>
1 Ba 1
2 Cl 2
4 H 4
2 O 2
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<u><em>
Balanced!!!
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