In which changes do the particles move further apart? W Х gas liquid solid Y Z

What is the molecular formula of a compound whose molar mass is 88.0 and whose percent composition is 54.5% carbon, 9.1% hydroge

Ray Of Light [21]

Answer:

C4H8O2

Explanation:

The molar mass of the compound we're looking for is 88.

54.5% of 88 is 4, this is how many carbons will be in the compound.

9.1% of 88 is 8, this is your hydrogens.

and 36.4% of 88 is roughly 3, however if you subtract the previous amounts to round down, you get 2; the oxygen amount.

Combine them all and you get C4H8O2

8 0

3 years ago

How many joules of energy are produced when 3.0 × 10-28 kilograms of mass are lost? [(1 j = 1 ) and the speed of light = 3.00 ×

Aleksandr [31]

The equation that we are going to use on this problem is the famous Einstein field equation. E = mc^2 where E is the energy (to be computed), m is the mass (3.0 × 10-28 kilograms) and c is the speed of light (3.00 × 10^8). If we plug in the given into the equation the answer will be 2.7*10^-11 KJ or 2.7*10^-8 J.

8 0

3 years ago

As the elements of group 16 (VIA) are considered from top to bottom on the Periodic Table, the atomic radii

mina [271]

For group 16 elements, the atomic radii increases down the group as a shell of electron is added on each time.

4 0

3 years ago

"An aqueous CaCl2 solution has a vapor pressure of 83.1mmHg at 50 ∘C. The vapor pressure of pure water at this temperature is 92

Lynna [10]

Answer : The the concentration of $CaCl_2$ in mass percent is, 41.18 %

Solution : Given,

Molar mass of water = 18 g/mole

Molar mass of $CaCl_2$ = 110.98 g/mole

First we have to calculate the mole fraction of solute.

According to the relative lowering of vapor pressure, the vapor pressure of a component at a given temperature is equal to the mole fraction of that component of the solution multiplied by the vapor pressure of that component in the pure state.

$\fac{p^o-p_s}{p^o}=X_B$

where,

$p^o$ = vapor pressure of the pure component (water) = 92.6 mmHg

$p_s$ = vapor pressure of the solution = 83.1 mmHg

$X_B$ = mole fraction of solute, $(CaCl_2)$

Now put all the given values in this formula, we get the mole fraction of solute.

$\fac{92.6-83.1}{92.6}=X_B$

$X_B=0.102$

Now we have to calculate the mole fraction of solvent (water).

As we know that,

$X_A+X_B=1\\\\X_A=1-X_B\\\\X_A=1-0.102\\\\X_A=0.898$

The number of moles of solute and solvent will be, 0.102 and 0.898 moles respectively.

Now we have to calculate the mass of solute, $(CaCl_2)$ and solvent, $(H_2O)$ .

$\text{Mass of }CaCl_2=\text{Moles of }CaCl_2\times \text{Molar mass of }CaCl_2$

$\text{Mass of }CaCl_2=(0.102mole)\times (110.98g/mole)=11.32g$

$\text{Mass of }H_2O=\text{Moles of }H_2O\times \text{Molar mass of }H_2O$

$\text{Mass of }H_2O=(0.898mole)\times (18g/mole)=16.164g$

Mass of solution = Mass of solute + Mass of solvent

Mass of solution = 11.32 + 16.164 = 27.484 g

Now we have to calculate the mass percent of $CaCl_2$

$Mass\%=\frac{\text{Mass of}CaCl_2}{\text{Mass of solution}}\times 100=\frac{11.32g}{27.484g}\times 100=41.18\%$

Therefore, the the concentration of $CaCl_2$ in mass percent is, 41.18 %

4 0

3 years ago

How do you work out question 1a?

Sliva [168]

Answer:

-125 kJ

Explanation:

You calculate the energy required to break all the bonds in the reactants. Then you subtract the energy to break all the bonds in the products.

H₂C=CH₂ + H₂ ⟶ H₃C-CH₃

Bonds: 4C-H + 1C=C 1H-H 6C-H + 1C-C

D/kJ·mol⁻¹: 413 612 436 413 347

The formula relating ΔHrxn and bond dissociation energies (D) is

ΔHrxn = Σ(Dreactants) – Σ(Dproducts)

(Note: This is an exception to the rule. All other thermochemical reactions are “products – reactants”. With bond energies, it’s “reactants – products”. The reason comes from the way we define bond energies.)

For the reactants:

Σ(Dreactants) = 4 × 413 + 1 × 612 + 1 × 436 = 2700 kJ

For the products:

Σ(Dproducts) = 6 × 413 + 1 × 347 = 2825 kJ

For the system :

ΔHrxn = 2700 - 2825 = -125 kJ

4 0

3 years ago