All categories

1 year ago

2. As elements go down a group, they have a whole

Chemistry

1 answer:

Stels [109]1 year ago

3 0

Answer:

Increases

Explanation:

Atomic size is the amount of space between the nucleus of an atom and the outermost electron. So, as each additional energy level is added, the overall amount of space between the nucleus and the outermost electron increases because there is now an extra shell of electrons that is farther out.

You might be interested in

What are the answers to the blanks to make this equation balanced

Eddi Din [679]

1Al+6NaOH==>2 $Na_{3}$ Al $O_{3}$ +3 $H_{2}$

Hope this helps!

5 0

2 years ago

A chemist must dilute of aqueous sodium carbonate solution until the concentration falls to . He'll do this by adding distilled

Mademuasel [1]

The question is incomplete, complete question is :

A chemist must dilute 73.9 mL of 400 mM aqueous sodium carbonate solution until the concentration falls to 125 mM . He'll do this by adding distilled water to the solution until it reaches a certain final volume. Calculate this final volume, in liters. Be sure your answer has the correct number of significant digits.

Answer:

The final volume of the solution will be 0.236 L.

Explanation:

Concentration of sodium carbonate solution before dilution = $M_1= 400 mM$

Volume of sodium carbonate solution before dilution = $V_1=73.9 mL$

Concentration of sodium carbonate solution after dilution = $M_2= 125 mM$

Volume of sodium carbonate solution after dilution = $V_2=?$

Dilution equation is given by:

$M_1V_1=M_2V_2$

$V_2=\frac{M_1V_1}{M_2}$

$V_2=\frac{400 mM\times 73.9 mL}{125 mM}= 236.48 mL\approx 236 mL$

1 mL = 0.001 L

236 mL = 0.236 L

The final volume of the solution will be 0.236 L.

3 0

2 years ago

Acetylene burns in air according to the following equation: C2H2(g) + 5 2 O2(g) → 2 CO2(g) + H2O(g) ΔH o rxn = −1255.8 kJ Given

professor190 [17]

Answer: -227 kJ

Explanation:

The balanced chemical reaction is,

$C_2H_2(g)+\frac{5}{2}O_2(g)\rightarrow 2CO_2(g)+H_2O(g)$

The expression for enthalpy change is,

$\Delta H=\sum [n\times \Delta H_f(product)]-\sum [n\times \Delta H_f(reactant)]$

$\Delta H=[(n_{CO_2}\times \Delta H_{CO_2})+ n_{H_2O}\times \Delta H_{H_2O})]-[(n_{C_2H_2}\times \Delta H_{C_2H_2})+(n_{O_2}\times \Delta H_{O_2})]$

where,

n = number of moles

$\Delta H_{O_2}=0$ (as heat of formation of substances in their standard state is zero

Now put all the given values in this expression, we get

$-1255.8=[(2\times -393.5)+(1\times -241.8)]-[(1\times \Delta H_{C_2H_2})+(\frac{5}{2}\times 0)]$

$-1255.8=[(-787)+(-241.8)]-[(1\times \Delta H_{C_2H_2})+(0)]$

$\Delta H_{C_2H_2}=-227kJ$

Therefore, the enthalpy change for $C_2H_2$ is -227 kJ.

7 0

2 years ago

Can someone help me?!!!!!

tangare [24]

Answer:

Subtract all the variables and do the opposite operation when added.

Explanation:

4 0

2 years ago

Which physical property and change in matter is utilized by distillation to separate two liquids in a mixture?

Schach [20]

Answer:

Boiling points

Liquid to gas

Explanation:

For distillation, the differences in boiling points of the liquids in the column is utilized for this separation.

The change in matter involved a state change of liquid to vapor or gaseous form.

Distillation is used to separate different liquids in a mixture.
A liquid - liquid mixture is separated into components due to their appreciable boiling point differences.
The method is used for purifying liquids.
The solution is boiled in a distillation flask to vaporization.

5 0

2 years ago