The question is incomplete, the complete question is;
In a laboratory experiment, students synthesized a new compound and found that when 12.23 grams of the compound were dissolved to make 228.1 mL of a benzene solution, the osmotic pressure generated was 4.55 atm at 298 K. The compound was also found to be non-volatile and a non-electrolyte. What is the molecular weight they determined for this compound?
Answer:
287.76 g/mol
Explanation:
From;
π
=
M
R
T
M = molarity
R= gas constant
T = temperature
number of moles = π * volume/RT
number of moles = 4.55 * 228.1/1000/0.082 * 298
number of moles = 1.037855/24.436
number of moles = 0.0425 moles
Molar mass = mass/number of moles
Molar mass = 12.23 grams/0.0425 moles
Molar mass = 287.76 g/mol
First, we need the balanced equation: H₂ + Cl₂ ---> 2HCl
since not much information is given, I am assuming we are at STP and that 22.4 Liters= 1 mol
1) let's convert the volume to moles using the molar volume of a gas. also we need to convert the cm₃ to mL, then to Liters.
8 cm³ (1 ml/ 1 cm³)(1 L/ 1000 mL) (1 mol/ 22.4 Liters)= 3.6x10⁻⁴ moles of H₂
2) let's use the mole ratio of the balanced equation to convert moles of H₂ to moles of HCl
3.6x10⁻⁴ mol H₂ (2 mol HCl/ 1 mol H₂)= 7.1x10⁻⁴ mol HCl
3) lastly, we convert the moles of HCl to grams using the molar mass.
molar mass of HCl= 1.01 + 35.5= 36.51 g/mol
7.1x10⁻⁴ mol HCl (36.51 g/mol)=<span> 0.026 grams HCl</span>
Answer:
The sum of first 30 terms of the arithmetic progression is <u>2160.</u>
Explanation:
For an arithmetic progression, the sum of first 
terms with first term as 
and common difference 
is given as:
Now, it is given that:
Now, plug in these values and frame two equations in 
Now, we solve equations (1) and (2) for . Subtract equation (1) from equation (2). This gives,
Now, plug in the value of 
in equation (1) and solve for .
Plug in the values of 
in the sum formula to find the sum of first 30 terms.
Now, the sum of first 30 terms is given as:
Therefore, the sum of first 30 terms of the arithmetic progression is 2160.
Answer: The empirical formula is 
Explanation:
If percentage are given then we are taking total mass is 100 grams.
So, the mass of each element is equal to the percentage given.
Mas of H = 1.8 g
Mass of S = 56.1 g
Mass of O = 42.1 g
Step 1 : convert given masses into moles.
Moles of H =
Mass of S =
Moles of O=
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For H = 
For S =
For O =
Converting to whole number ratios
The ratio of H: S: O= 2: 2: 3
Hence the empirical formula is
B. It is open to change as new evidence or data is discovered. If scientists discover new evidence, they must modify their theories to conform with the new data.
A. is <em>incorrect</em>. Scientific laws are so well established that there can be no exceptions.
C. is <em>incorrect</em>. A scientific theory is the collective judgement of scientists as to the best explanation for a phenomenon. A new observation may require modification of the theory.
D. is <em>incorrect</em>. Advancements in technology can provide new evidence that requires new explanations.
