Answer:
there are 9 Chlorine atoms
Explanation:
Answer:
The correct answer is 146 g/mol
Explanation:
<em>Freezing point depression</em> is a colligative property related to the number of particles of solute dissolved in a solvent. It is given by:
ΔTf = Kf x m
Where ΔTf is the freezing point depression (in ºC), Kf is a constant for the solvent and m is the molality of solution. From the problem, we know the following data:
ΔTf = 1.02ºC
Kf = 5.12ºC/m
From this, we can calculate the molality:
m = ΔTf/Kf = 1.02ºC/(5.12ºC/m)= 0.199 m
The molality of a solution is defined as the moles of solute per kg of solvent. Thus, we can multiply the molality by the mass of solvent in kg (250 g= 0.25 kg) to obtain the moles of solute:
0.199 mol/kg benzene x 0.25 kg = 0.0498 moles solute
There are 0.0498 moles of solute dissolved in the solution. To calculate the molar mass of the solute, we divide the mass (7.27 g) into the moles:
molar mass = mass/mol = 7.27 g/(0.0498 mol) = 145.9 g/mol ≅ 146 g/mol
<em>Therefore, the molar mass of the compound is 146 g/mol </em>
Question:
A chemistry student needs of 10 g isopropenylbenzene for an experiment. He has available 120 g of a 42.7% w/w solution of isopropenylbenzene in acetone. Calculate the mass of solution the student should use. If there's not enough solution, press the "No solution" button.
Answer:
The answer to the question is as follows
The mass of solution the student should use is 23.42 g.
Explanation:
To solve the question we note the following
A solution containing 42.7 % w/w of isopropenylbenzene in acetone has 42.7 g of isopropenylbenzene in 100 grams of the solution
Therefore we have 10 g of isopropenylbenzene contained in
100 g * 10 g/ 42.7 g = 23.42 g of solution
Available solution = 120 g
Therefore the quantity to used from the available solution = 23.42 g of the isopropenylbenzene in acetone solution.
It would be an physical change ; if you melt butter the butter goes from a solid to a liquid so therefore the physical state is changed.
Answer:
gold wire (Au)
Explanation:
A substance that cannot be separated or broken down into simpler substances by chemical means is an element.
Between the given options only gold wire is an element, Au.
A way of knowing that it is an element is noticing that its formula is a single symbol which corresponds to an element found in the periodic table, unlike a combination of said symbols (like NaCl or H₂O).
