ΔHrxn = ΣδΗ(bond breaking) - ΣδΗ(bond making)
Bond enthalpies,
N ≡ N ⇒ 945 kJ mol⁻¹
N - Cl ⇒ 192 kJ mol⁻¹
Cl - Cl⇒ 242 kJ mol⁻¹
According to the balanced equation,
ΣδΗ(bond breaking) = N ≡ N x 1 + Cl - Cl x 3
= 945 + 3(242)
= 1671 kJ mol⁻¹
ΣδΗ(bond making) = N - Cl x 3 x 2
= 192 x 6
= 1152 kJ mol⁻¹
δHrxn = ΣδΗ(bond breaking) - ΣδΗ(bond making)
= 1671 kJ mol⁻¹ - 1152 kJ mol⁻¹
= 519 kJ mol⁻¹
Answer:
approximately 15.1 grams.
Explanation:
The key to chemistry is to change everything to moles. Then when you have the answer in moles change the answer back to grams, liters, or whatever you want.
change 25 grams of potassium chlorate to moles.
calculate the gram molecular mass of potassium chlorate.
Chlorate is Cl with 3 oxygens. ate = saturated. Chlorine has seven valance electrons when it is saturated six of these electrons are used by oxygen ( 2 electrons per oxygen) leaving only 1 electron.
1 K x 39 grams/mole
+1 Cl x 35.4 grams/ mole
+3 O x 16 grams/ mole
= 122.4 grams / mole Potassium Chlorate
25
122.4
= moles.
2.05 moles of Potassium Chlorate.
There is a 1:1 mole ratio. 1 mole of Potassium Chlorate will produce 1 mole of Potassium Chloride.
2.05 moles of Potassium Chlorate will produce 2.05 moles of Potassium Chloride.
Find the gram molecular mass of Potassium Chloride.
1 K x 39 = 39
+1 Cl x 35.4 = 35.4
= 74.4 grams / mole.
2.05 moles x 74.4 grams/ mole = 15.2 grams
Hope it helps :)
1. Physical
2. Chemical
3. Physical
4. Physical
5. Chemical
6. I really don't feel like doing 6, sorry.
7. False: energy to mass
11. False: change to exothermic
12. False: change to endothermic
A chemist (from Greek chēm (ía) alchemy; replacing chemist from Medieval Latin alchimista[1]) is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties. Chemists carefully describe the properties they study in terms of quantities, with detail on the level of molecules and their component atoms. Chemists carefully measure substance proportions, reaction rates, and other chemical properties. The word 'chemist' is also used to address Pharmacists in Commonwealth English.
<u>Answer:</u> The correct answer is geographical map.
<u>Explanation:</u>
Model is defined as the three dimensional representation of a proposed structure in a smaller scale.
For the given options:
<u>Option 1:</u> PV = nRT
This is a proposed law. This law is known as ideal gas law. A law is defined as the rule which defined a correct procedure. For any gas behaving ideally, this law is used.
<u>Option 2:</u> Geographical map
Map is defined as the diagrammatic representation of an area of land or sea which also shows physical features, roads, cities etc..
A 3-D model can be prepared for geographical map.
<u>Option 3:</u> I believe that aliens exist
This is a hypothetical statement. It is a smart guess by the means of set of assumptions and observations. For its validation, we need to conduct some experiments.
Hence, the correct answer is geographical map.
