Two difference between molecular formula and molecular weight<br>please help :((

What type of observation can be stated with just numbers?

djverab [1.8K]

Answer:

D. Quantitative

Explanation:

Quantitative observation deals with numbers, or amounts.

Qualitative observation deals with de- scriptions that cannot be expressed in numbers.

7 0

3 years ago

The gas left in a used aerosol can is at a pressure of 103 kPa at 25.0 °C. If the can heats up to 50.0 °C, what is the pressure

Anton [14]

The question mentions a change in temperature from 25 to 50 °C. With that, the aim of the question is to determine the change in volume based on that change in temperature. Therefore this question is based on Gay- Lussac's Gas Law which notes that an increase in temperature, causes an increase in pressure since the two are directly proportional (once volume remains constant). Thus Gay-Lussac's Equation can be used to solve for the answer.
Boyle's Equation: $\frac{P_{1} }{T_{1} }$ = $\frac{P_{2} }{T_{2} }$
Since the initial temperature (T₁) is 25 C, the final temperature is 50 C (T₂) and the initial pressure (P₁) is 103 kPa, then we can substitute these into the equation to find the final pressure (P₂).
$\frac{P_{1} }{T_{1} }$ = $\frac{P_{2} }{T_{2} }$ ∴ by substituting the known values, ⇒ (103 kPa) ÷ (25 °C) = (P₂) ÷ (50 °C)
⇒ P₂ = (4.12 kPa · °C) (50 °C)
= 206 kPa
Thus the pressure of the gas since the temperature was raised from 25 °C to 50 °C is 206 kPa

3 0

3 years ago

What is the standard electrode potential for a galvanic cell constructed in the appropriate way from these two half-cells?

____ [38]

E

θ

Cell

=

+

2.115

l

V

Cathode

Mg

2

+

/

Mg

Anode

Ni

2

+

/

Ni

Explanation:

Look up the reduction potential for each cell in question on a table of standard electrode potential like this one from Chemistry LibreTexts. [1]

Mg

2

+

(

a

q

)

+

2

l

e

−

→

Mg

(

s

)

−

E

θ

=

−

2.372

l

V

Ni

2

+

(

a

q

)

+

2

l

e

−

→

Ni

(

s

)

−

E

θ

=

−

0.257

l

V

The standard reduction potential

E

θ

resembles the electrode's strength as an oxidizing agent and equivalently its tendency to get reduced. The reduction potential of a Platinum-Hydrogen Electrode under standard conditions (

298

l

K

,

1.00

l

kPa

) is defined as

0

l

V

for reference. [2]

A cell with a high reduction potential indicates a strong oxidizing agent- vice versa for a cell with low reduction potentials.

Two half cells connected with an external circuit and a salt bridge make a galvanic cell; the half-cell with the higher

E

θ

and thus higher likelihood to be reduced will experience reduction and act as the cathode, whereas the half-cell with a lower

E

θ

will experience oxidation and act the anode.

E

θ

(

Ni

2

+

/

Ni

)

>

E

θ

(

Mg

2

+

/

Mg

)

Therefore in this galvanic cell, the

Ni

2

+

/

Ni

half-cell will experience reduction and act as the cathode and the

Mg

2

+

/

Mg

the anode.

The standard cell potential of a galvanic cell equals the standard reduction potential of the cathode minus that of the anode. That is:

E

θ

cell

=

E

θ

(

Cathode

)

−

E

θ

(

Anode

)

E

θ

cell

=

−

0.257

−

(

−

2.372

)

E

θ

cell

=

+

2.115

Indicating that connecting the two cells will generate a potential difference of

+

2.115

l

V

across the two cells.

5 0

2 years ago

Read 2 more answers

Q82. Liquid petrol does not ignite spontaneously when exposed to the air because

sashaice [31]

Liquid petrol does not ignite spontaneously when exposed to the air because there is not enough molecules that contains energy to reach the activation energy. As a result, the reaction cannot proceed and a supply of energy should be added for the reaction to occur.

7 0

3 years ago

Which is a property of barium (Ba)?

pogonyaev

Answer:

a it rarely reach with other elements

6 0

3 years ago

Two difference between molecular formula and molecular weightplease help :((​

Two difference between molecular formula and molecular weightplease help :((