Answer: Another useful feature of the periodic table is that most tables provide all the information you need to balance chemical reactions at a glance. The table tells each element's atomic number and usually its atomic weight. The typical charge of an element is indicated by its group.
Explanation:
Answer:
1) Fe = 69.9%
O = 31.1%
2) H = 5.19%
O = 16.5%
N = 28.9%
C = 49.5%
Explanation:
One easy way to do percent compositions is to assume you have 100g of a substance.
1) Lets say we have 100g of Fe2O3.
The total molar mass would be:
The molar mass of the Fe2 alone is:
Thus, the grams of Fe2(out of a 100) could be calculated by multiplying 100g * the molar mass ratio of Fe2 to the whole:
Which is approximately 69.9%.
We can find the amount of O3 by simply subtracting, as the rest of the compound is made of O3. Thus, the % composition of O3 is 31.1%
You can then do this same process to the next question, getting us the following:
H = 5.19%
O = 16.5%
N = 28.9%
C = 49.5%
Answer:
185.05 g.
Explanation
Firstly, It is considered as a stichiometry problem.
From the balanced equation: 2LiCl → 2Li + Cl₂
It is clear that the stichiometry shows that 2.0 moles of LiCl is decomposed to give 2.0 moles of Li metal and 1.0 moles of Cl₂, which means that the molar ratio of LiCl : Li is (1.0 : 1.0) ratio.
We must convert the grams of Li metal (30.3 g) to moles (n = mass/atomic mass), atomic mass of Li = 6.941 g/mole.
n = (30.3 g) / (6.941 g/mole) = 4.365 moles.
Now, we can get the number of moles of LiCl that is needed to produce 4.365 moles of Li metal.
Using cross multiplication:
2.0 moles of LiCl → 2.0 moles of Li, from the stichiometry of the balanced equation.
??? moles of LiCl → 4.365 moles of Li.
The number of moles of LiCl that will produce 4.365 moles of Li (30.3 g) is (2.0 x 4.365 / 2.0) = 4.365 moles.
Finally, we should convert the number of moles of LiCl into grams (n = mass/molar mass).
Molar mass of LiCl = 42.394 g/mole.
mass = n x molar mass = (4.365 x 42.394) = 185.05 g.
The answer to this question is 6.25ml
To answer this question, you need to calculate the azithromycin drug doses for this patient. The calculation would be: 25kg * 10mg/kg/d= 250mg/d
Then multiply the doses with the available drug. It would be:
250 mg/d / (200mg/5ml)= 6.25ml/d
Explanation:
(Ques- A) Why does the first method for determining volume work only for a regular-shaped object?
<u>(Ans- A)</u> <em>Because the method requires precise dimensions of objects for result, which is not possible for irregular shaped objects.</em>
(Ques - B) Will the second method for determining volume work for any object or just an odd-shaped one? Why?
<u>(Ans-B)</u> <em>It will work for both regular and irregular shaped objects since both displace equal volumes of water.</em>
(Ques - C) Is one method of measurement more accurate than the other? Why or why not?
<u>(Ans-C)</u> <em>Both are pretty accurate, with some experimental errors which may creep in accidentally. </em>
(Ques- D) Would the displacement method of measurement work for a cube of sugar? What about a cork? Why?
<u>(Ans - D)</u> <em>No, the method would not work because sugar being soluble, will dissolve in water. </em>
<em>No, the method would not work because sugar being soluble, will dissolve in water. Cork is less dense than water so floats on it, with only part of it submerged in water, resulting in displacement of less volume of water than actual volume of Cork.</em>
(Ques-E) What did you find out from this investigation? Be thoughtful in your answer.
<u>(Ans- E)</u> <em>I learnt about determining volume of different objects from this investigation. </em>(Sorry, I know its not a very thoughtful answer)
