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3 years ago

Which atom has the largest atomic radius? potassium rubidium Francium cesium

Chemistry

1 answer:

suter [353]3 years ago

5 0

Francium has the largest atomic radius.

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An organic compound contains , , , and . Combustion of 0.1023 g of the compound in excess oxygen yielded 0.2587 g and 0.0861 g .

Kisachek [45]

The question displayed below shows the missing information which therefore completes the question.

An organic compound contains C, H, N and O. Combustion of 0.1023 g of the compound in excess oxygen yielded 0.2587 g of CO2 and 0.0861 g of H2O. A sample of 0.4831 g of the compound was analyzed for nitrogen by the Dumas method. The compound is first reacted by passage over hot: The product gas is then passed through a concentrated solution of to remove the. After passage through the solution, the gas contains and is saturated with water vapor. At STP, 38.9 mL of dry N2 was obtained. In a third experiment, the density of the compound as a gas was found to be 2.86 g/L at 127°C and 256 torr. What are the empirical and molecular formulas of the compound? (Enter the elements in the order: C, H, N, O.)

Answer:

the empirical formula = $\mathbf {C_3H_6O_{12}N}$

the molecular formula = $\mathbf {C_3H_6O_{12}N}$

Explanation:

From the given information:

$\bigg ( 0.2587 \ g \ of CO_2 \bigg) \times \dfrac{1 \ mol \ of CO_2}{44 \ of \ CO_2} \times \dfrac{1 \ mol \ of \ C}{1 \ mol \ of CO_2}$

$= 0.00588 \ mol \ of \ C \times \dfrac{12.01 \ g \ of \ C}{1 \ mol \ of \ C }$

= 0.0706g of C

$\bigg ( 0.0861\ g \ of H_2O \bigg) \times \dfrac{1 \ mol \ of H_2O}{18.02 \ g \ of \ H_2O} \times \dfrac{2 \ mol \ of \ H}{1 \ mol \ of H_2O}$

$=0.0096 \ mol \times \dfrac{1.008 \ g \ of \ H}{1 mol \ H}$

0.0097g of H

Given that N2 at STP = 1 atm, 273 K and V = 0.0389 L

PV = nRT

n = PV/RT

$n = \dfrac{1 \ atm \times 0.0389 \ of \ H_2}{0.0821 \ L.atm /mol.K \times 273 \ K }$

n = 0.00173 mol of N2

The oxygen in the sample = The total grams in sample - gram in H - gram in C

The oxygen in the sample = 0.1023 g - 0.0097 g - 0.706 g

The oxygen in the sample = 0.022 g of O

The number of moles of $O_2 = \dfrac{0.02}{16}$

= 0.001375 mol of O

$O \ in \ product = (0.00588 \ mol \ of \ C ) \times \dfrac{2 \ mol \ of \ O }{1 \ mol \ of \ C }+ \bigg ( 0.0096 \ mol \ of \ H ) \times \dfrac{1 \ mol \ of \ O }{1 \ mol \ of \ H}$

O in product = 0.02136 mol of O

∴

we are meant to divide the moles of each compound by the smallest number of moles; we have:

$C = \dfrac{0.00588}{0.00173} \simeq 3$

$H = 0.0096 = \dfrac{0.0096}{0.00173} \simeq 6$

$O = 0.0199= \dfrac{0.0199}{0.00173} \simeq 12$

$N = 0.00173= \dfrac{0.00173}{0.00173} \simeq 1$

Thus; the empirical formula = $\mathbf {C_3H_6O_{12}N}$

To estimate the molecular formula; we have:

$MM = \dfrac{dRT}{P}$

$MM = \dfrac{2.80 \ g/ L \times 0.0821 \ L.atm /mol.K \times 400 \ K }{0.337 \ atm}$

MM = 272.86 g/mol

Also; the molar mass of $\mathbf {C_3H_6O_{12}N}$ = 248 g/mol

∴

$= \dfrac{272.86 \ g/mol}{248 \ g/mol}$

$=1$

Thus; we can conclude that empirical formula as well as the molecular formula are the same.

6 0

3 years ago

Wenzhou prepares 200 mL of a solution of SnCl4in which the concentration ofchloride ions is 0.240M.a) What is the molarity of th

nalin [4]

Answer: a) 0.06 M

b) 3.13 grams.

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.

$Molarity=\frac{moles}{\text {Volume in L}}$

Moles of $Cl^-=Molarity\times {\text {Volume in L}}=0.240\times 0.2L=0.048moles$

The balanced reaction for dissociation will be:

$SnCl_4\rightarrow Sn^{4+}+4Cl^{-}$

Thus for 4 moles of $Cl^-$ , there is 1 mole of $SnCl_4$

Thus moles of $SnCl_4=\frac{1}{4}\times 0.048=0.012$

Molarity of $SnCl_4=\frac{moles}{\text {Volume in L}}=\frac{0.012}{0.2L}=0.06M$

Thus the molarity of the $SnCl_4$ solution = 0.06 M

b) Mass of $SnCl_4$ = $moles\times {\text {Molar mass}}=0.012mol\times 260.522g/mol=3.13g$

Thus mass of $SnCl_4$ Wenzhou use is 3.13 grams.

7 0

3 years ago

Read 2 more answers

When a runner participates in a marathon, they travel a distance of 26.2 miles. How many kilometers is

jolli1 [7]

Answer:

Around 42.2 Km

Explanation:

7 0

3 years ago

Elements are organized on the periodic table according to

Alex

Answer:

atomic number

Explanation:

The periodic table is a table that lists all of the chemical elements in order of atomic number, starting with hydrogen and ending with oganesson. The number of protons in the nucleus of an atom of a certain element is its atomic number.

Have a good day :)

5 0

3 years ago

What important processes in your body depend on mitosis

PilotLPTM [1.2K]

Mitosis makes new cells and replaces the cells that are old, lost or damaged

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3 years ago