All categories

3 years ago

What are the rows of the periodic table of the elements also called?

Chemistry

2 answers:

lesya [120]3 years ago

4 0

The rows are called Periods.

Anon25 [30]3 years ago

4 0

The answer is:

B) Periods

Hope it helps!

You might be interested in

Fill in the blanks in the following sentences:

Nezavi [6.7K]

Answer:

a. neutral

b. basic /alkaline

c. acidic

4. 13

4 0

3 years ago

Freon−12 (CF2Cl2), widely used as a refrigerant and aerosol propellant, is a dangerous air pollutant. In the troposphere, it tra

nevsk [136]

Answer:

141g of CCl₄

Explanation:

First, we have to write the balanced equation.

CCl₄(g) + 2 HF(g) ⇄ CF₂Cl₂(g) + 2 HCl(g)

We can calculate how many moles of CF₂Cl₂ using the ideal gas equation.

V = 14.9 dm³ = 14.9 L

T = 21°C + 273.15 = 294.15 K

P = 1.48 atm

R = 0.08206 atm.L/mol.K

$P.V=n.R.T\\n=\frac{P.V}{R.T} =\frac{1.48atm.14.9L}{0.08206\frac{atm.L}{mol.K}.294.15K }=0.914mol$

We can use proportions to find the mass of CCl₄ required to obtain 0.914 moles of CF₂Cl₂. According to the balanced equation, 1 mol of CF₂Cl₂ is produced when 1 mol of CCl₄ reacts. And the molar mass of CCl₄ is 154 g/mol.

$0.914molCF_{2}Cl_{2}.\frac{1molCCl_{4}}{1molCF_{2}Cl_{2}} .\frac{154gCCl_{4}}{1molCCl_{4}} =141gCCl_{4}$

7 0

3 years ago

What is the speed of a bobsled whose distance-time graph indicates that it traveled 112m in 29s?

nordsb [41]

Well to find speed you have to do distance /time. So, in this case you do 112m /29s which it will be 3.862 which if you round it, it will be 3.86 m/s

4 0

3 years ago

Read 2 more answers

The osmotic pressure exerted by a solution is equal to the molarity multiplied by the absolute temperature and the gas constant

zavuch27 [327]

Answer: M = 22/ (i x28.948)

Explanation:

Pi = osmotic pressure = 22atm

T = Temperature = 353K

M = Molarity = ?

R = gas constant = 0.082atm.L/mol/K

i = van’t Hoff factor

Pi = iMRT

M= Pi /(iRT) = 22 / ( i x 0.082 x 353)

M = 22/ (i x28.948)

7 0

3 years ago

) PABA refers to para-aminobenzoic acid which is used in some sunscreen formulations. If a 0.055 M solution of PABA has a pH of

AleksandrR [38]

Answer: $K_a$ of PABA is 0.000022

Explanation:

$NH_2C_6H_5COOH\rightarrow H^++NH_2C_6H_5COO^-$

cM 0 0

$c-c\alpha$ $c\alpha$ $c\alpha$

So dissociation constant will be:

$K_a=\frac{(c\alpha)^{2}}{c-c\alpha}$

Give c= 0.055 M and $\alpha$ = ?

$K_a=?$

$pH=-log[H^+]$

$2.96=-log[H^+]$

$[H^+]=1.09\times 10^{-3}$

$[H^+]=c\times \alpha$

$1.09\times 10^{-3}=0.055\times \alpha$

$\alpha=0.02$

Putting in the values we get:

$K_a=\frac{(0.055\times 0.02)^2}{(0.055-0.055\times 0.02)}$

$K_a=0.000022$

Thus $K_a$ of PABA is 0.000022

5 0

2 years ago