Answer:

Explanation:
We are asked to find the mass of a sample of metal. We are given temperatures, specific heat, and joules of heat, so we will use the following formula.

The heat added is 4500.0 Joules. The mass of the sample is unknown. The specific heat is 0.4494 Joules per gram degree Celsius. The difference in temperature is found by subtracting the initial temperature from the final temperature.
- ΔT= final temperature - initial temperature
The sample was heated <em>from </em> 58.8 degrees Celsius to 88.9 degrees Celsius.
- ΔT= 88.9 °C - 58.8 °C = 30.1 °C
Now we know three variables:
- Q= 4500.0 J
- c= 0.4494 J/g°C
- ΔT = 30.1 °C
Substitute these values into the formula.

Multiply on the right side of the equation. The units of degrees Celsius cancel.

We are solving for the mass, so we must isolate the variable m. It is being multiplied by 13.52694 Joules per gram. The inverse operation of multiplication is division, so we divide both sides by 13.52694 J/g

The units of Joules cancel.


The original measurements have 5,4, and 3 significant figures. Our answer must have the least number or 3. For the number we found, that is the ones place. The 6 in the tenth place tells us to round the 2 up to a 3.

The mass of the sample of metal is approximately <u>333 grams.</u>
Answer:
Ball and stick model is 3D and has the atoms depicted as different Coloured balls Conected to each other by "sticks"
fischer projection has the atoms on the side coming out of the plane, the atoms at the ends going behind (going away from you)
bond line notation Is the most common it does not show the C or H bonds but instead carbons are represented by the bends
Answer : The fraction of carbonic acid present in the blood is 5.95%
Explanation :
The mixture consists of carbonic acid ( H₂CO₃) and bicarbonate ion ( HCO₃⁻). This represents a mixture of weak acid and its conjugate which is a buffer.
The pH of a buffer is calculated using Henderson equation which is given below.
![pH = pKa + log \frac{[Base]}{[Acid]}](https://tex.z-dn.net/?f=pH%20%3D%20pKa%20%2B%20log%20%5Cfrac%7B%5BBase%5D%7D%7B%5BAcid%5D%7D)
We have been given,
pH = 7.5
pKa of carbonic acid = 6.3
Let us plug in the values in Henderson equation to find the ratio Base/Acid.
![7.5 = 6.3 + log \frac{[base]}{[acid]}](https://tex.z-dn.net/?f=7.5%20%3D%206.3%20%2B%20log%20%5Cfrac%7B%5Bbase%5D%7D%7B%5Bacid%5D%7D)
![1.2 = log \frac{[base]}{[acid]}](https://tex.z-dn.net/?f=1.2%20%3D%20log%20%5Cfrac%7B%5Bbase%5D%7D%7B%5Bacid%5D%7D)
![\frac{[Base]}{[Acid]} = 10^{1.2}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BBase%5D%7D%7B%5BAcid%5D%7D%20%3D%2010%5E%7B1.2%7D)
![\frac{[Base]}{[Acid]} = 15.8](https://tex.z-dn.net/?f=%5Cfrac%7B%5BBase%5D%7D%7B%5BAcid%5D%7D%20%3D%2015.8)
![[Base] = 15.8 \times [Acid]](https://tex.z-dn.net/?f=%5BBase%5D%20%3D%2015.8%20%5Ctimes%20%5BAcid%5D)
The total of mole fraction of acid and base is 1. Therefore we have,
![[Acid] + [Base] = 1](https://tex.z-dn.net/?f=%5BAcid%5D%20%2B%20%5BBase%5D%20%3D%201)
But Base = 15.8 x [Acid]. Let us plug in this value in above equation.
![[Acid] + 15.8 \times [Acid] = 1](https://tex.z-dn.net/?f=%5BAcid%5D%20%2B%2015.8%20%5Ctimes%20%5BAcid%5D%20%3D%201)
![16.8 [Acid] = 1](https://tex.z-dn.net/?f=16.8%20%5BAcid%5D%20%3D%201)
![[Acid] = \frac{1}{16.8}](https://tex.z-dn.net/?f=%5BAcid%5D%20%3D%20%5Cfrac%7B1%7D%7B16.8%7D)
![[Acid] = 0.0595](https://tex.z-dn.net/?f=%5BAcid%5D%20%3D%200.0595)
[Acid] = 0.0595 x 100 = 5.95 %
The fraction of carbonic acid present in the blood is 5.95%