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liraira [26]
2 years ago
5

What is the molal concentration of a solution made by dissolving 34.2 g of sucrose, c12h22o11 (molar mass 342.34 g/mol), in 125

g of water?
Chemistry
2 answers:
Anna007 [38]2 years ago
7 0
Molality is the number of moles of solute in 1 kg of solvent
number of moles of sucrose - mass of sucrose / molar mass
number of moles of sucrose - 34.2 g / 342.34 g/mol = 0.0999 mol
number of moles in 125 g of water - 0.0999 mol 
therefore number of moles in 1000 g - 0.0999 / 125 x 1000 = 0.799 mol/kg
molality of sucrose solution - 0.799 mol/kg
Alborosie2 years ago
6 0

Answer:

0.799 mol

Explanation:

Molality is the number of moles of solute in 1 kg of solvent

number of moles of sucrose - mass of sucrose / molar mass

therefore number of moles in 1000 g - 0.0999 / 125 x 1000 = 0.799 mol

Molality of sucrose solution - 0.799 mol

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chubhunter [2.5K]

Answer:

See explanation

Explanation:

Hydrogen has a valency of +1 or -1. Its electronic configuration is 1s1.

The 1s sub-level (first shell) is known to hold two electrons. This means that hydrogen may either loose this one electron in the 1s level to yield H^+ or accept another electron into this 1s level to form H^- (the hydride ion).

The formation of the hydride ion completes the 1s orbital.

4 0
2 years ago
Calculate the enthalpy of combustion, δh∘comb, for c6h14. you'll first need to determine the balanced chemical equation for the
Vedmedyk [2.9K]
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3 0
2 years ago
Now explain your diagnosis. Start your argument by writing something like this: "My group believes that Elisa has/does not have
likoan [24]

Answer:

Explanation:I would need more info to understand this question but explaining molecules is pretty easy tho

4 0
1 year ago
When a 3.22 g sample of an unknown hydrate of sodium sulfate, na2so4 ⋅ h2o(s), is heated, h2o (molar mass 18 g) is driven off. T
Mariana [72]

The value of X is 10 hence the formula of unknown hydrate   sodium sulfate is  NaSO4.10 H20

calculation

step 1:find the moles of NaSO4 and the moles of H2O

moles= mass/molar mass

moles of Na2SO4=1.42÷142=0.01 moles

moles of H20=  mass of H2O/molar mass of H2O

mass of H2O= 3.22-1.42=1.8g

mole of H2O is therefore 1.8÷18=0.1 moles

step 2: find the mole ratio by dividing each mole by smallest number of mole (0.01)

that is Na2So4= 0.01/0.01 =1

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6 0
2 years ago
Platinum, which is widely used as a catalyst, has a work function φ(the minimum energy needed to eject an electron from the meta
Arlecino [84]

Answer:

A. \lambda_0=2.196\times 10^{-7}\ m

Explanation:

The work function of the Platinum = 9.05\times 10^{-19}\ J

For maximum wavelength, the light must have energy equal to the work function. So,

\psi _0=\frac {h\times c}{\lambda_0}

Where,  

h is Plank's constant having value 6.626\times 10^{-34}\ Js

c is the speed of light having value 3\times 10^8\ m/s

\lambda_0 is the wavelength of the light being bombarded

\psi _0=Work\ function

Thus,

9.05\times 10^{-19}=\frac {6.626\times 10^{-34}\times 3\times 10^8}{\lambda_0}

\frac{9.05}{10^{19}}=\frac{19.878}{10^{26}\lambda_0}

9.05\times \:10^{26}\lambda_0=1.9878\times 10^{20}

\lambda_0=2.196\times 10^{-7}\ m

8 0
1 year ago
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