Answer:
This question is incomplete, the remaining part of the question is:
What is the control group, independent variable and dependent variable?
Control group: Plants placed in 80 degree rooms
Independent variable: Change in temperature
Dependent variable: Change in color of leaves
Explanation:
The independent variable in a scientific experiment is the variable that the experimenter controls or manipulates in order to bring about a change in the dependent variable. In this experiment, the variable manipulated by Justin B is the TEMPERATURE CHANGE.
On the other hand, a variable is said to be dependent if it is the variable that responds to a change made to the independent variable or rather it is the outcome. In this experiment, Justin B is trying to see the outcome on the color change in leaves when exposed to a low temperature, hence, COLOR CHANGE IN LEAVES is the dependent variable.
Control group of an experiment is the group that receives no experimental treatment. It is the group the experimenter considers normal and hence is comparing with his experimental group. In this experiment, Justin B believes the leaves change color in a low temperature, hence, he placed some plants in a lower temperature (60 degree) in order to compare them with when the plants are placed in a higher temperature (80 degree). As far as this experiment is concerned, the plants placed in 80 degrees temperature are believed by Justin B not to undergo color change, hence, they are the CONTROL GROUP while the group he placed in 60 degrees temperature are what he is interested in, making them the EXPERIMENTAL GROUP
Answer : The 
ion concentration is, 
and the pH of a buffer is, 2.95
Explanation : Given,
Concentration of 
(weak acid)= 0.26 M
Concentration of 
(conjugate base or salt)= 0.89 M
First we have to calculate the value of 
.
The expression used for the calculation of is,
Now put the value of 
in this expression, we get:
Now we have to calculate the pH of the solution.
Using Henderson Hesselbach equation :
![pH=pK_a+\log \frac{[Salt]}{[Acid]}](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%20%5Cfrac%7B%5BSalt%5D%7D%7B%5BAcid%5D%7D)
![pH=pK_a+\log \frac{[KNO_2]}{[HNO_2]}](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%20%5Cfrac%7B%5BKNO_2%5D%7D%7B%5BHNO_2%5D%7D)
Now put all the given values in this expression, we get:
The pH of a buffer is, 2.95
Now we have to calculate the ion concentration.
![pH=-\log [H_3O^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH_3O%5E%2B%5D)
![2.95=-\log [H_3O^+]](https://tex.z-dn.net/?f=2.95%3D-%5Clog%20%5BH_3O%5E%2B%5D)
![[H_3O^+]=1.12\times 10^{-3}M](https://tex.z-dn.net/?f=%5BH_3O%5E%2B%5D%3D1.12%5Ctimes%2010%5E%7B-3%7DM)
The ion concentration is,
Answer:
atom is the smallest unit of ordinary matter that forms a chemical element. Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. Atoms are extremely small, typically around 100 picometers across.
Answer:
0.054 mol O
Explanation:
<em>This is the chemical formula for acetic acid (the chemical that gives the sharp taste to vinegar): CH₃CO₂H. An analytical chemist has determined by measurements that there are 0.054 moles of carbon in a sample of acetic acid. How many moles of oxygen are in the sample?</em>
<em />
Step 1: Given data
- Chemical formula of acetic acid: CH₃CO₂H
- Moles of carbon in the sample: 0.054 moles
Step 2: Establish the appropriate molar ratio
According to the chemical formula, the molar ratio of C to O is 2:2.
Step 3: Calculate the moles of oxygen in the sample
We will use the molar ratio to determine the moles of oxygen accompanying 0.054 moles of carbon.
0.054 mol C × (2 mol O/2 mol C) = 0.054 mol O
Solute of solution = 17.8 g
Solvn = 198 g
% = 17.8 / 198
w% = 0.089 x 100 = 8.9% by mass
hope this helps!
