Answer:
A. electrons simultaneously attracted by more than one nucleus
Explanation:
- Covalent bond is the bond which is formed with the sharing of the electrons between the two atoms which are taking part in the bond. It is generally formed between the atoms with similar electronegativity values.
- It is the bond which is generally occurs within non metals as they share electrons to complete their octet.
- The difference in the electronegativity values of the atoms involving in a covalent bond must not exceed the value of 1.7 .
Thus, the electrons are attracted by the two different nucleus of the atoms that are taking part in the bonding.
<u>So, the correct answer is:- A. electrons simultaneously attracted by more than one nucleus</u>
<h3>
Answer:</h3>
89.88° C
<h3>
Explanation:</h3>
<u>We are given;</u>
- Mass of gold cylinder as 75 g
- specific heat of gold is 0.129 J/g°C
- Initial temperature of gold cylinder is 65°C
- Mass of water is 500 g
- Initial temperature of water is 90 °C
We are required to calculate the final temperature;
- We know that Quantity of heat is given by the product of mass, specific heat capacity and change in temperature.
<h3>Step 1: Calculate the quantity of heat absorbed by the Gold cylinder</h3>
Assuming the final temperature is X° C
Then; ΔT = (X-65)°C
Therefore;
Q = 75 g × 0.129 J/g°C × (X-65)°C
= 9.675X - 628.875 Joules
<h3>Step 2: Calculate the quantity of heat released by water</h3>
Taking the final temperature as X° C
Change in temperature, ΔT = (90 - X)° C
Specific heat capacity of water is 4.184 J/g°C
Therefore;
Q = 500 g × 4.184 J/g°C × (90 - X)° C
= 188,280 -2092X joules
<h3>Step 3: Calculate the final temperature, X°C</h3>
we know that the heat gained by gold cylinder is equal to the heat released by water.
9.675X - 628.875 Joules = 188,280 -2092X joules
2101.675 X = 188908.875
X = 89.88° C
Thus, the final temperature is 89.88° C
Answer:
0.038 g of reactant
Explanation:
Data given:
Heat release for each gram of reactant consumption = 36.2 kJ/g
mass of reactant that release 1360 J of heat = ?
Solution:
As 36.2 kJ of heat release per gram of reactant consumption so first we will convert KJ to J
As we know
1 KJ = 1000 J
So
36.2 kJ = 36.2 x 1000 = 36200 J
So it means that in chemical reaction 36200 J of heat release for each gram of reactant consumed so how much mass of reactant will be consumed if 1360 J heat will release
Apply unity formula
36200 J of heat release ≅ 1 gram of reactant
1360 J of heat release ≅ X gram of reactant
Do cross multiplication
X gram of reactant = 1 g x 1360 J / 36200 J
X gram of reactant = 0.038 g
So 0.038 g of reactant will produce 1360 J of heat.
Well, clearly the calculated value for the number of hydrating water molecules would increase above its true level, because the total weight loss would be greater than expected. This is of course undesirable, but may usually be avoided by careful application of the experimental procedures. The signs to look for include
<span>(a) loss of water of hydration usually occurs at a considerably lower temperature than decomposition of the salt, because the water molecules are not strongly bonded in the hydrated complex. Dehydration typically occurs in a broad range of temperatures, typically from 50°C to around 200°C, whereas decomposition of the dehydrated salt generally takes place at temperatures over 200°C and in some case over 1000°C. So dehydration should be performed with care - avoid over-heating the sample in order to ensure that all the water has been driven off. </span>
<span>(b) dehydration often results in a change of appearance of the sample, particularly the colour and particle size of crystalline hydrates. However, decomposition may be accompanied by an additional change at higher temperatures, which gives a warning of its occurrence. </span>
<span>(c) if it is suspected that decomposition is occurring, or that dehydration is not complete, exploratory runs of varying duration at a given temperature may be carried out. There are two criteria to judge the effectiveness of the procedure </span>
<span>(i) the weight of the sample decreases to a constant stable value: this is a sign that dehydration is complete and decomposition - which is usually a much slower process - is not occurring. </span>
<span>(ii) the calculated number of molecules of water lost should take an integer value. If it differs by more than, say, 0.1 from an integer than it is probable that one of these two undesirable effects is present. Some hydrates lose water in steps through intermediate compounds with a lower level of hydration. These may provide plateaus where the weight loss is stable but dehydration is not complete. These will, in general, not provide an integer value for the number of water molecules present (because the calculation is based on the assumption that the residual sample is completely dehydrated salt).</span>
Answer:
The answer is 4.28 moles
Explanation:
This is super easy okay, you won't forget this!
Basically mole ratios, we're just looking at the coefficients in front of the compounds, multiplying them, and dividing them as we see fit.
In this example, you can see how you need 2 moles of lithium bromide (LiBr) for the reaction, and 2 moles of lithium chloride (LiCl) will be produced.
Basically, the <u>molar ratio</u> is when you divide numbers and see how much of this do I have for that (if that makes sense).
So if you were to divide the 2 moles of LiBr / 2 moles of LiCl = 1. So we know that the mole ratio for LiBr to LiCl is 1:1 or 2:2, either or, it's the same thing.
SO THE BIG IDEA, if we have 4.28 moles of lithium bromide reacting, we should also have 4.28 moles of lithium chloride produced, BECAUSE the <u>mole ratio</u> is 1:1.
I hope this makes sense please tell me if it doesn't, I will try my best to explain a little more.
