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3 years ago

Which element is in group 2 and period 7 of the periodic table

Chemistry

1 answer:

bekas [8.4K]3 years ago

3 0

Hey
Sorry, But There Is No 7th Element in group two. only six which is Radium.
~Spades15

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At 25.0 ° C, a 10.00 L vessel is filled with 5.25 moles of Gas A and 7.05 moles of Gas B. What is the total pressure?

abruzzese [7]

Answer:

P = 30.1 atm

Explanation:

Given data:

Temperature of vessel = 25°C

Volume of vessel = 10.00 L

Moles in vessel = A + B = 5.25 mol + 7.05 mol = 12.3 moles

Total pressure inside vessel = ?

Solution:

The given problem will be solve by using general gas equation,

PV = nRT

P= Pressure

V = volume

n = number of moles

R = general gas constant = 0.0821 atm.L/ mol.K

T = temperature in kelvin

Now we will convert the temperature.

25+273 = 298 K

P = nRT/V

P = 12.3 mol × 0.0821 atm.L/ mol.K × 298 K / 10.00 L

P = 300.93 / 10.00 L

P = 30.1 atm

7 0

3 years ago

Calculate the pH of a solution prepared by dissolving 0.370 mol of formic acid (HCO2H) and 0.230 mol of sodium formate (NaCO2H)

Veronika [31]

The question is incomplete, here is the complete question:

Calculate the pH of a solution prepared by dissolving 0.370 mol of formic acid (HCO₂H) and 0.230 mol of sodium formate (NaCO₂H) in water sufficient to yield 1.00 L of solution. The Ka of formic acid is 1.77 × 10⁻⁴

a) 2.099

b) 10.463

c) 3.546

d) 2.307

e) 3.952

<u>Answer:</u> The pH of the solution is 3.546

<u>Explanation:</u>

We are given:

Moles of formic acid = 0.370 moles

Moles of sodium formate = 0.230 moles

Volume of solution = 1 L

To calculate the molarity of solution, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

To calculate the pH of acidic buffer, we use the equation given by Henderson Hasselbalch:

$pH=pK_a+\log(\frac{[salt]}{[acid]})$

$pH=pK_a+\log(\frac{[HCOONa]}{[HCOOH]})$

$pK_a$ = negative logarithm of acid dissociation constant of formic acid = 3.75

$[HCOONa]=\frac{0.230}{1}$

$[HCOOH]=\frac{0.370}{1}$

pH = ?

Putting values in above equation, we get:

$pH=3.75+\log(\frac{0.23/1}{0.37/1})\\\\pH=3.54$

Hence, the pH of the solution is 3.546

5 0

3 years ago

In a chemical process, the amount of a certain type of impurity in the output is difficult to control and is thus a random varia

Julli [10]

Answer:

+/- 0.00033

Explanation:

For a 95 % confidence interval the range is given by

+/- Z * s/sqrt(n)

where Z value is 1.916 for a 95% confidence interval

Therefore the interval is

s is the standard deviation in this case 0.0015

n is 75 the number of outposts

calculating,

+/- 1.916 * 0.0015/sqrt(75) = +/- 0.00033

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2 years ago

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In a college of exactly 2760 students, exactly 65 % are male. What is the number of female students? Express your answer as an i

lina2011 [118]

Total number of students (male and female) in the college=2760. Total number of students including both male and female represents 100% (percentage) of students which is equal to 2760 number.

Number of male students is 65% (percentage) which is equal to $\frac{2760X65}{100}$ = 1794. So, total number of female students are (100-65)%=35% (percentage) which is equal to $\frac{2760X35}{100}$ =966 numbers.

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2 years ago

Atoms in 1 mol of carbon dioxide

astra-53 [7]

1 carbon and 2 oxygen atoms CO2

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2 years ago