Physical change. Physical changes are changes affecting the form of a chemical substance, but not its chemical composition. ... Physical changes occur when objects or substances undergo a change that does not change their chemical composition.
<u>Answer:</u> The molecular balanced equation is written below
<u>Explanation:</u>
A molecular equation is defined as the chemical equation in which the ionic compounds are written as molecules rather than component ions.
A balanced chemical equation is defined as the equation in which total number of individual atoms on the reactant side is equal to the total number of individual atoms on product side.
The balanced chemical equation for the decomposition of bromine trifluoride follows:
By Stoichiometry of the reaction:
2 moles of bromine trifluoride produces 1 mole of bromine gas and 3 moles of fluorine gas
Hence, the molecular balanced equation is written above.
Weight percentage of nitrogen can be calculated using the following rule:
weight percentage of nitrogen = (weight of nitrogen / weight of urea) x 100
From the periodic table:
molecular mass of carbon = 12 grams
molecular mass of nitrogen = 14 grams
molecular mass of hydrogen = 1 grams
molecular mass of oxygen = 16 grams
therefore:
mass of nitrogen in urea = 2(14) = 28 grams
mass of urea = 12 + 2(14) + 4(1) + 16 = 60 grams
Substitute with the masses in the equation to get the percentage:
weight percentage of nitrogen = (28/60) x 100 = 46.667%
Answer:
T = 377.2 K, Less than
Explanation:
The thermodynamic quantity used in predicting whether a reaction is spontaneous or not is the gibbs free energy.
It's relationship with ΔH⁰ and ΔS⁰ is given as;
ΔG° = ΔH° - TΔS°
Basically, a negative value of ΔG° means the reaction is spontaeneous.
To obtain the calculated vale of T,
ΔS° = ΔH°/T
T = ΔH° / ΔS°
T = 377.2 K
Let's calculate the value of ΔG° at that temperature.
ΔG° = ΔH° - TΔS°
ΔG° = − 46700 - 377.2(− 123.8)
ΔG° = 0 (approximately, values are due to the rounding off)
At ΔG° = 0 the reaction is at equilibrium.
To find if the reaction is spontaneous at lower or hugher temperature than the calculated temperature, we would be substituting the value of T with a smaller (random) value and also a larger (random) value.
Larger T (390K)
ΔG° = ΔH° - TΔS°
ΔG° = − 46700 - 390(− 123.8)
ΔG° = - 46700 + 48,282
ΔG° = 1582 J/mol
Smaller T (350K)
ΔG° = ΔH° - TΔS°
ΔG° = − 46700 - 350(− 123.8)
ΔG° = - 46700 + 43330
ΔG° = -3370J/mol
This means the temperature would be lesser than the calculated value for it to be spontaneus.
Answer:
Closed packet together and they only can vibrate.
Explanation: Solids can have a crystalline or amorphous structure.
