Answer:
C they are moving away from each other
Explanation:
Answer:
This question is asking to identify the variables in the experiment
Independent variable: different salt concentration
Dependent variable: Height of plants
Control group: Plants that receive pure water
Experimental group: Plants that receive different concentration of the salt water solution
Explanation:
The independent variable is the variable that is manipulated or changed by the experimenter in order to bring about a measurable outcome. In this experiment, the independent variable is the DIFFERENT SALT CONCENTRATION the plants were exposed to.
The dependent variable is the variable that responds to the change or manipulation of the independent variable or the measured variable. In this experiment, the dependent variable is the HEIGHT OF THE PLANTS.
The experimental group refers to the group that receives the experimental treatment. The experimental group in this experiment are the PLANTS THAT RECEIVE DIFFERENT CONCENTRATION OF SALT SOLUTIONS.
The control group does not receive any experimental treatment as the independent variable is unchanged. The control group is the PLANT THAT RECEIVE PURE WATER i.e no salt solution
Cool to know im not that interested, but cool to know
<span>Avogadro's number
represents the number of units in one mole of any substance. This has the value
of 6.022 x 10^23 units / mole. This number can be used to convert the number of
atoms or molecules into number of moles.
</span>6.89 × 10^25 molecules CO2 ( 1 mole / 6.022 x 10^23 molecules ) ( 44.01 g / mole ) = 5035.35 g CO2 = 5.035 kg CO2
Answer:
A
Explanation:
First, we're given that the atmospheric pressure is 744.8 mmHg. However, this includes the pressure of the Zinc and the pressure of the water; we only want the pressure of the water, so subtract its pressures (23.8 mmHg) from 744.8 mmHg: 744.8 - 23.8 = 721 mmHg.
Now, we can use the ideal gas law: PV = nRT.
- the pressure P is 721 mmHg
- the volume V is 7.80 L
- the moles n of Zinc is what we want to find in order to calculate the mass
- the gas constant R is 62.36 L mmHg / (mol K)
- the temperature T is 25.0°C, or 25.0 + 273 = 298 K
Plug all these in:
PV = nRT
(721 mmHg) * (7.80 L) = n * (62.36) * (298 K)
n ≈ 0.303 mol Zn
We need to convert this to grams, so use the molar mass of Zinc, which is 65.38 g/mol:
![0.303molZn*\frac{65.38g}{1mol} =19.8gZn](https://tex.z-dn.net/?f=0.303molZn%2A%5Cfrac%7B65.38g%7D%7B1mol%7D%20%3D19.8gZn)
Thus, the answer is A.