A form of
electricity which can attract things is static electricity. Static electricity
is the result of an imbalance between negative and positive charges in an
object. These charges built up o the surface of an object until they find a way
to e released or discharged causing the attraction of things.
Answer:
II) Objects made of silver become tarnished.
Explanation:
Physical properties are the properties which can be observed without changing identity of substance.
Chemical properties are the properties which describe how the substance changes into the different substance completely.
Boiling is an example of physical change in state of the substance. Color is also an example of physical property like boiling point and hence these are constants. The reason of the color is that the chromium ions shows certain colors as the electrons are excited due to absorption of the light. The tarnishing of the silver is an example of the chemical change which occurs due to the reaction of the silver with oxygen. This is also known as corrosion.
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%
Answer:
Ca
Explanation:
It is on the left side of the periodic table where metals are located.
Answer:
The empirical formula would be N₂Os * Page 2 Calculate the empirical formulaof a compound that is 94.1% oxygen, 5.9% hydrogen.