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3 years ago

What are these means in Periodic Table; Group Period Block

1 answer:

5 0

1. Group: Groups shows the number of valence electrons and are shown in columns on the periodic table.

2. Period: Periods show the number of energy levels each element has and are shown in rows on the periodic table (up and down).

3. Blocks are show the amount of orbitals each element has. There is an s block, d block, p block, and f block.

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A 25.0 ml sample of an hcl solution is titrated with a 0.139 m naoh solution. the equivalence point is reached with 15.4 ml of b

Andreas93 [3]

the balanced equation for the acid base reaction is as follows

NaOH + HCl ---> NaCl + H₂O

stoichiometry of NaOH to HCl is 1:1

the number of NaOH moles is - 0.139 mol/L x 0.0154 L = 0.00214 mol

the number of NaOH moles reacted = number of HCl moles reacted

therefore number of HCl moles reacted = 0.00214 mol

volume of HCl containing 0.00214 mol - 25.0 mL

number of HCl moles in 25.0 mL - 0.00214 mol

therefore number of HCl moles in 1000 mL - 0.00214 mol / 25.0 mL x 1000 mL/L

molarity of HCl is 0.0856 mol/L

concentration of HCl is 0.0856 M

5 0

3 years ago

Read 2 more answers

A flexible container at an initial volume of 6.13 L contains 6.51 mol of gas. More gas is then added to the container until it r

aivan3 [116]

Answer:

the final mole of the flexible container = 12.92 moles

Explanation:

Given that :

initial volume of a flexible container = 6.13 L

initial mole of a flexible container = 6.51 mol

final volume of a flexible container = 18.3 L

final mole of a flexible container = ???

Assuming the pressure and temperature of the gas remain constant, calculate the number of moles of gas added to the container.

Therefore,

$n= \dfrac{V_2*n_1}{V_1}$

$n= \dfrac{18.3*6.51}{6.13}$

n = 19.43

$n=n_1+n_2$

19.43 = 6.51 + n₂

n₂ = 19.43 - 6.51

n₂ = 12.92 moles

Thus; the final mole of the flexible container = 12.92 moles

6 0

3 years ago

What is the average isotopic mass of an element that has the following abundances in nature? Isotopic mass: X20 X22 X23 Abundanc

Paladinen [302]

Answer: 20.2

Explanation:

Mass of isotope 1 = 20

% abundance of isotope 1 = 90.5% = $\frac{90.5}{100}=0.905$

Mass of isotope 2 = 22

% abundance of isotope 2 = 8.0% = $\frac{8}{100}=0.08$

Mass of isotope 3 = 23

% abundance of isotope 3 = 1.5% = $\frac{1.5}{100}=0.015$

Formula used for average atomic mass of an element :

$\text{ Average atomic mass of an element}=\sum(\text{atomic mass of an isotopes}\times {{\text { fractional abundance}})$

$A=\sum[(20\times 0.905+(22\times 0.08)+(23\times 0.015]$

$A=20.2$

Therefore, the average atomic mass of the element is 20.2.

8 0

3 years ago

What is the number of carbon atoms in the ring portion of the haworth structure of glucose?

Anna35 [415]

I have attached the picture ot the H<span>aworth structure of glucose.

You can count in total 6 carbon atoms but only 5 are in the ring portion of the structure.

Therefore, the answer is 5.
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8 0

3 years ago

How many grams are in 7.32 x 1023 molecules of potassium carbonate (K2CO3)?

tiny-mole [99]

(I leave off the x10^23 because they both will divide out) Use your per

7 0

2 years ago