Definition: A one or two letter abbreviation for a chemical element.<br> Example: Cu is copper.

Question 14 A student dissolves 1.5g of styrene C8H8 in 225.mL of a solvent with a density of 1.02/gmL . The student notices tha

Yuki888 [10]

We must to know:

Cm = molarity = niu / Vs, when the niu = no. of moles and Vs = Volume of solution

the no. niu = mass / molecular mass of substance

molecular mass of C8H8 = 12x8+8x1 = 104 g/mol

=> niu = 1,5 / 104 = 0,0144 moles C8H8

=> Cm = 0,0144/0,225 = 0,06 mol/L

Cmm = molality = niu (C8H8) / mass of solvent (kg)

=> p = mass / V => mass (solvent) = p x V

=> 225 x 1,02 = 229,5 g solvent = 0,2295 kg solvent

=> Cmm = 0,0144 / 0,229,5 = 0,063

8 0

2 years ago

Read 2 more answers

Zachary adds 26.64 g to 12.557 g. How many significant figures should his answer have?

asambeis [7]

This answer should have four signifigant features

Explanation:

I had this on a test and got it right :D

5 0

3 years ago

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A mixture of 0.10 mol of NO, 0.050 mol of H2, and 0.10 mol of H2O is placed in a 1.0- L vessel at 300 K . The following equilibr

umka2103 [35]

Answer:

The concentration of N2 at the equilibrium will be 0.019 M

Explanation:

Step 1: Data given

Number of moles of NO = 0.10 mol

Number of moles of H2 = 0.050 mol

Number of moles of H2O = 0.10 mol

Volume = 1.0 L

Temperature = 300K

At equilibrium [NO]=0.062M

Step 2: The balanced equation

2NO(g) + 2H2(g) → N2(g) + 2H2O(g)

Step 3: Calculate the initial concentration

Concentration = Moles / volume

[NO] = 0.10 mol / 1L = 0.10 M

[H2] = 0.050 mol / 1L = 0.050 M

[H2O] = 0.10 mol / 1L = 0.10 M

[N2] = 0 M

Step 4: Calculate the concentration at the equilibrium

[NO] at the equilibrium is 0.062 M

This means there reacted 0.038 mol (0.038M) of NO

For 2 moles NO we need 2 moles of H2 to produce 1 mol N2 and 2 moles of H2O

This means there will also react 0.038 mol of H2

The concentration at the equilibrium is 0.050 - 0.038 = 0.012 M

There will be porduced 0.038 moles of H2O, this means the final concentration pf H2O at the equilibrium is 0.100 + 0.038 = 0.138 M

There will be produced 0.038/2 = 0.019 moles of N2

The concentration of N2 at the equilibrium will be 0.019 M

5 0

3 years ago

If the temperature of a gas is increased from 20°C to 35°C, what is the new pressure if the original pressure was 1.2 atm? Assum

Marta_Voda [28]

Answer:

B.) 1.3 atm

Explanation:

To find the new pressure, you need to use Gay-Lussac's Law:

P₁ / T₁ = P₂ / T₂

In this equation, "P₁" and "T₁" represent the initial pressure and temperature. "P₂" and "T₂" represent the final pressure and temperature. After converting the temperatures from Celsius to Kelvin, you can plug the given values into the equation and simplify to find P₂.

P₁ = 1.2 atm P₂ = ? atm

T₁ = 20 °C + 273 = 293 K T₂ = 35 °C + 273 = 308 K

P₁ / T₁ = P₂ / T₂ <----- Gay-Lussac's Law

(1.2 atm) / (293 K) = P₂ / (308 K) <----- Insert values

0.0041 = P₂ / (308 K) <----- Simplify left side

1.3 = P₂ <----- Multiply both sides by 308

3 0

1 year ago

C4H9OH(g)+O2(g)→CO2(g)+?H2O(l) what coefficient should be placed in front of H2O to balance the hydrogen atoms?

slava [35]

Answer:

5

Explanation:

To balance the hydrogen atoms, we check the number of hydrogen on the left side, this is equal to the 10 hydrogen atoms we have in the alkanol.

Now, on the right hand side, we can see we only have two hydrogen atoms in the water molecule. Now, to make equal the number of hydrogen atoms on both sides, we simply multiply the number of hydrogen there by 5 to make it 10 too

3 0

2 years ago

Definition: A one or two letter abbreviation for a chemical element. Example: Cu is copper.