Answer: picture shows work for # 1,2,4,5,7
Explanation:
number 3: as the pressure in the volume decreases, the volume increases causing it to expand and eventually blow.
number 6: because the temperature and the amount of gas don’t change, these terms don’t appear in the equation. What Boyle’s law means is that the volume of a mass of gas is inversely proportional to its pressure. This linear relationship between pressure and volume means doubling the volume of a given mass of gas decreases its pressure by half.
hope this helps :))
This uses the concept of freezing point depression. When faced with this issue, we use the following equation:
ΔT = i·Kf·m
which translates in english to:
Change in freezing point = vant hoff factor * molal freezing point depression constant * molality of solution
Because the freezing point depression is a colligative property, it does not depend on the identity of the molecules, just the number of them.
Now, we know that molality will be constant, and Kf will be constant, so our only unknown is "i", or the van't hoff factor.
The van't hoff factor is the number of atoms that dissociate from each individual molecule. The higher the van't hoff factor, the more depressed the freezing point will be.
NaCl will dissociate into Na+ and Cl-, so it has i = 2
CaCl2 will dissociate into Ca2+ and 2 Cl-, so it has i = 3
AlBr3 will dissociate into Al3+ and 3 Br-, so it has i = 4
Therefore, AlBr3 will lower the freezing point of water the most.
You must use 134 g O₂ to produce 118 g H₂O.
M_r: 32.00 18.02
2H₂ + O₂ ⟶ 2H₂O
Moles of H₂O = 150.9 g H₂O × (1 mol H₂O/18.02 g H₂O) = 8.374 mol H₂O
Moles of O₂ = 8.374 mol H₂O × (1 mol O₂/2 mol H₂O) = 4.187 mol O₂
Mass of O₂ = 4.1877 mol O₂ × (32.00 g O₂/1 mol O₂) = 134 g O₂
Answer : The atomic mass of chlorine is, 36.723 amu
Explanation :
Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.
Formula used to calculate average atomic mass follows:
As we are given that,
Mass of 35-Cl isotope = 35 amu
Percentage abundance of 35-Cl isotope = 13.85 %
Fractional abundance of 35-Cl isotope = 0.1385
Mass of 37-Cl isotope = 37 amu
Percentage abundance of 37-Cl isotope = 86.15 %
Fractional abundance of 37-Cl isotope = 0.8615
Now put all the given values in above formula, we get:
![\text{Average atomic mass }=[(35\times 0.1385)+(37\times 0.8615)]](https://tex.z-dn.net/?f=%5Ctext%7BAverage%20atomic%20mass%20%7D%3D%5B%2835%5Ctimes%200.1385%29%2B%2837%5Ctimes%200.8615%29%5D)
Therefore, the atomic mass of chlorine is, 36.723 amu
The sample A, prepared with water instead with vinegar, is called control sample.
It is important to prepare a control sample for comparison purposes.
Using a contral sample the scientist try to discard effects that could drive to erronous conclusions.
The scientific will compare the observations on what happens to the samples with vinegar with the observations on the sample with water. If the sample with water is treated in the same way that the samples with vinegar, and the results are different, the scientific may conclude the effect of the vinegar, but is the sample with water shows a similar behavior to that of the samples with vinegar, the scientific will know that it is not the vinegar but another variable the responsible of the effect.
