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3 years ago

What do the coefficients located before certain molecules in each chemical equation represent?

1 answer:

6 0

It represents the number of moles required of that molecule to balance the chemical equation, which means to have the reaction chemically happen and goes to completion.

For example:
CH4 + O2 --> H2O + CO2 that is not balanced

with the coefficients located
CH4 + 2O2 --> 2H2O + CO2 now with the coefficients the number of oxygen and hydrogen on each side are equal

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what is the balanced net ionic equation for the reaction in acidic solution of fe2+ and kmno4 (fe2+ becomes ff3+ and MnO4 become

sveticcg [70]

The balanced half reactions are
4 Fe2+ ====> 4 Fe3+ + 4 e-

MnO42- + 8 H+ + 4 e- ===> Mn2+ + 4 H2O

The net ionic equation is
4 Fe2+ + MnO42- + 8 H+ ===> 4 Fe3+ + Mn2+ + 4 H2O

4 0

3 years ago

The area that deals with the mechanism, the rate, and the energy transfer that occurs when matter undergoes a change

mafiozo [28]

Physical chemistry is the area that deals with the mechanisms, the rate, and the energy transfer that occurs when matter undergoes a change. So the correct option for the given question is option “B”. Whenever there is a change in the state of matter, the physical properties definitely undergo a change. A solid matter will always have a definite shape and volume, while a liquid has a definite volume but no shape. Gases do not have either definite volume or shape. Chemical properties might not be affected, but physical properties are definitely impacted when a matter undergoes change.

7 0

3 years ago

Jamie rolls a 6-sided die 30 times and determines that the experimental probability of rolling a 2 is Start Fraction 1 over 15 E

anyanavicka [17]

Answer:

Conduct more trials

Explanation:

Theoretical Probability can be defined as what someone is expecting to happen

Experimental Probability on the other hand, is defined as what actually happens.

Probability is usually calculated in the same way for experimental probability and that of theoretical probability. You divide the total number of possible ways in which a particular outcome can happen, by the total number of outcomes itself.

In Experimental probability, the more times a probability is tried, it gets closer and even more closer to theoretical probability.

So, for the question, Jamie should improve the number of tries more, so as to get his experimental probability results to be closer to the theoretical probability result.

8 0

3 years ago

How many molecules of Mg3N2 (magnesium nitride) are formed when excess Mg (magnesium)

dybincka [34]

Explanation:

3Mg(s) + N2(g) = Mg3N2(s)

First check that the equation is balanced. In this case, it is.

Assuming that magnesium is the limiting reactant:

First find the molecular weight using the Periodic Table.

We find that the atomic mass of magnesium is approximately

24.3g, so the molecular weight is just 24.3g\mol

2. Next we need the mole to mole ratio. As there are 3

magnesiums for 1 magnesium nitride (shown by the coefficients), the

mole to mole ratio is 1 mol Mg3N2\3 mol Mg.

3. We need the amount of the substance, in grams. Since you have not

stated it in the question, I'll just do 10g AS AN EXAMPLE. Note that

depending on the amount, the LIMITING REAGENT MAY DIFFER.

4. Finally, we need the molecular weight of Mg3N2, which we can easily

calculate to be around 100.9\mol.

5. Putting this all together, we have 10gMg⋅ (mol Mg\24.3gMg)

(1mol Mg3N2\ 3mol Mg) (100.9g Mg3N2\mol Mg3N2)

the units will cancel to leave gMg3N2 (grams of magnesium nitride):

10gMg ⋅ (mol Mg\24.3gMg) (1mol Mg3N2\3mol Mg)

(100.9g Mg3N2\mol Mg3N2)

Doing the calculation yields approximately 13.84g.

Assuming that nitrogen is the limiting reactant:

Similarly, following the above steps but with 10g of nitrogen yields 36.04g

In conclusion, as we produce less amount of Mg3N2 when we assumed that Mg was the limiting reagent, magnesium is the limiting reagent and nitrogen is the excess.

Note: This is in THIS CASE, where we have 10g of both. The answer may vary depending on the amount of each substance.

7 0

3 years ago

Read 2 more answers

Explain how you can use boyle's law to determine the new volume of gas when its pressure is increased from 270 kPa to 540 kPa? T

LUCKY_DIMON [66]

There are several information's already given in the question. Based on the information's the answer can be easily deduced.

We know the formula

P1*V1/T1 = P2*V2/T2

As the temperature is constant, so T1 and T2 can be negated. The formula changes to
P1*V1 = P2*V2
70 * 1 = 540 * V2
270/540 = V2
V2 = 0.5

From the above deduction, we can conclude that the new volume is 0.5 liters. I hope that the procedure is clear enough for you to understand.

7 0

4 years ago