Answer:
Matter
Compound
Explanation:
Caffeine is NOT an Element, because it is formed by different elements (C, H, N, and O).
Caffeine is NOT an Isotope, because this only applies to elements with the same atomic number but different mass number.
Caffeine is Matter because it has mass and occupies space by having volume.
Caffeine is a Compound because it has a formula with a <em>definite constant composition</em> of different elements.
<span>C2Br2
First, we need to determine how many moles of the gas we have. For that, we'll use the Ideal Gas Law which is
PV = nRT
where
P = pressure (1.10 atm = 111458 Pa)
V = volume (10.0 ml = 0.0000100 m^3)
n = number of moles
R = Ideal gas constant (8.3144598 (m^3 Pa)/(K mol) )
T = Absolute temperature
Solving for n, we get
PV/(RT) = n
Now substituting our known values into the formula.
(111458 Pa * 0.0000100 m^3) / (288.5 K * 8.3144598 (m^3 Pa)/(K mol))
= (1.11458/2398.721652) mol
= 0.000464656 mol
Now let's calculate the empirical formula for this compound.
Atomic weight carbon = 12.0107
Atomic weight bromine = 79.904
Relative moles carbon = 13.068 / 12.0107 = 1.08802984
Relative moles bromine = 86.932 / 79.904 = 1.087955547
So the relative number of atoms of the two elements is
1.08802984 : 1.087955547
After dividing all numbers by the smallest, the ratio becomes
1.000068287 : 1
Which is close enough to 1:1 for me to consider the empirical formula to be CBr
Now calculate the molar mass of CBr
12.0107 + 79.904 = 91.9147
Finally, let's determine if the compound is actually CBr, or something like C2Br2, or some other multiple. Using the molar mass of CBr, multiply by the number of moles and see if the result matches the mass of the gas. So
91.9147 g/mol * 0.000464656 mol = 0.042708701 g
0.0427087 g is a lot smaller than 0.08541 g. So the compound isn't exactly CBr. Let's divide them to see what the factor is.
0.08541 / 0.0427087 = 1.99982673
1.99982673 is close enough to 2 to within the number of significant digits we have for me to claim that the formula for the unknown gas isn't CBr, but instead is C2Br2.</span>
The grams of 22.9 % sugar solution that contain 68.5 g of sugar is 299.13 g of solution
<u><em>calculation</em></u>
22.9% means that there are 22.9 g of sugar in 100 g of solution.
what about 68.5 g of sugar
- <em>by cross multiplication</em>
=[(68.5 g sugar x 100 g solution) /22.9 g sugar] =299.13 g of solution
Nb; <em>g sugar cancel each other</em>
Answer:
geez I have no clue sorry
