The balanced equation for the combustion of ethene is given below. If 97.7 g of oxygen is used, how much

An important natural and metallic resource is ?

ss7ja [257]

The answer is B.) Carbon

3 0

3 years ago

What is the boiling point of a solution containing 203 g of ethylene glycol (C2H6O2) and 1035 g of water? (Kb for water is 0.52

Andru [333]

Answer:

101,37°C

Explanation:

Boiling point elevation is one of the colligative properties of matter. The formula is:

ΔT = kb×m (1)

Where:

ΔT is change in boiling point: (X-100°C) -X is the boiling point of the solution-

kb is ebulloscopic constant (0,52°C/m)

And m is molality of solution (mol of ethylene glycol / kg of solution). Moles of ethylene glycol (MW: 62,07g/mol):

203g × (1mol /62,07g) = 3,27moles of ethlyene glycol

Molality is: 3,27moles of ethlyene glycol / (1,035kg + 0,203kg) = 2,64m

Replacing these values in (1):

X - 100°C = 0,52°C/m×2,64m

X - 100°C = 1,37°C

X = 101,37°C

I hope it helps!

7 0

3 years ago

Which elements have the quantum numbers (4,3,-2,+1/2) and (5,2,-1,-1/2)

nikklg [1K]

The elements are samarium (Sm) and silver (Ag).

Quantum numbers (4,3,-2,+½)

n = 4: Principal quantum number = 4.

l = 3: Element has 4f electrons

It is conventional to list quantum numbers in decreasing order.

Hund’s rule states that all the orbitals must be half-filled with electrons having the same spin before any can receive a second electron.

We get the following table:

Element n l mₗ mₛ

La 4 3 3 +½

Ce 4 3 2 +½

Pr 4 3 1 +½

Nd 4 3 0 +½

Pm 4 3 -1 +½

Sm 4 3 -2 +½

The element is samarium, Sm.

Quantum numbers (5,2,-1,-½)

n = 5: Principal quantum number = 5.

l = 2: Element has 5d electrons

We get the following table:

Element n l mₗ mₛ

Y 5 2 2 +½

Zr 5 2 1 +½

Nb 5 2 0 +½

Mo 5 2 -1 +½

Tc 5 2 -2 +½

Ru 5 2 2 -½

Rh 5 2 1 -½

Pd 5 2 0 -½

Ag 5 2 -1 -½

The element is silver, Ag.

Note: These assignments assume that there are no exceptions in the Periodic Table.

7 0

3 years ago

Write half reactions and the overall reaction occurred during discharging of acid lead battery.

Gre4nikov [31]

When battery discharge / delivering current the lead at the anode is oxidized
that is ;
pb---->pb+ 2e-
since the lead ions are in presence of aquous sulfate in insoluble lead sulfate precipitate onto the electrode
the overall reaction at the anode is therefore
Pb + SO4^2- ---> PbSO4 + 2e-

5 0

3 years ago

Two 10g blocks, one of copper and one of iron, were heated from 300 K to 400K (a temperature difference of 100 K).

vova2212 [387]

Energy absorbed by Iron block E (iron) = 460.5 J

Energy absorbed by Copper block E (Copper) = 376.8 J

Explanation:

To find the heat absorbed, we can use the formula as,

q = m c ΔT

Here, Mass = m = 10 g = 0.01 kg

ΔT = change in temperature = 400 - 300 = 100 K = 100 - 273 = -173 °C

c = specific heat capacity

c for iron = 460.5 J/kg K

c for copper = 376.8 J/kg K

Plugin the values in the above equation, we will get,

q (iron) = 0.01 kg × 460.5 J/kg K × 100 K

= 460.5 J

q (copper) = 0.01 kg × 376.8 J/kg K × 100 K

= 376.8 J

3 0

3 years ago