I think the correct answer would be the third option. From the physical change that happened, we can only tell that the mass of the plastic would be still the same and would weigh 15 grams. This is in accordance with the Law of conservation of mass where it states that mass cannot be destroyed or created. So, since it is only a physical change that happens the substance itself would still be the same and it is only the form that is changed, it would still have the same mass. However, with the change, the volume is changed and is said to increase which means it would greatly affect the density. Increasing the volume would result to a decrease in density.
0.04350179862
Explanation:
Make sure to check for sig figs though. Basically, you have 2.54 mL and you multiply that by the 0.789 g/mL and mL cancels out and you are left with 2.00406g. There are 46.06844 grams per mol of ethanol, so to cancel out grams we multiply by 1/46.06844. And then we are left with 0.04350179862 mol
Answer:
Electronegativity difference between 2 atoms
Explanation:
1. If the electronegativity difference (usually called ΔEN) is less than 0.5, then the bond is nonpolar covalent.
2. If the ΔEN is between 0.5 and 1.6, the bond is considered polar covalent
3. If the ΔEN is greater than 2.0, then the bond is ionic.
Answer:
C4H8O4
Explanation:
To determine the molecular formula, first, let us obtain the empirical formula. This is illustrated below:
From the question given, we obtained the following information:
C = 45.45%
H = 6.12%
O = 48.44%
Divide the above by their molar mass
C = 45.45/12 = 3.7875
H = 6.12/1 = 6.12
O = 48.44/16 = 3.0275
Divide by the smallest
C = 3.7875/3.0275 = 1
H = 6.12/3.0275 = 2
O = 3.0275/3.0275 = 1
The empirical formula is CH2O
The molecular formula is given by [CH2O]n
[CH2O]n = 132.12
[12 + (2x1) + 16]n = 132.12
30n = 132.12
Divide both side by the coefficient of n i.e 30
n = 132.12/30 = 4
The molecular formula is [CH2O]n = [CH2O]4 = C4H8O4
Let's solve ~
Initial concentration of weak acid HA = 0.200 M
and dissociation constant (
) is :
Now, at initial stage :
At equilibrium :
Now, we know :
![\qquad \sf \dashrightarrow \: { K_a = \dfrac{[H+] [A-]}{[HA]}}](https://tex.z-dn.net/?f=%5Cqquad%20%5Csf%20%20%5Cdashrightarrow%20%5C%3A%20%7B%20K_a%20%3D%20%5Cdfrac%7B%5BH%2B%5D%20%5BA-%5D%7D%7B%5BHA%5D%7D%7D%20)
( big brackets represents concentration )
