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2 years ago

9

An unknown compound in the lab is either LiOH, CaF2, or LiF. If the sample has a mass of 260 grams and contains 3.33 moles, what

is the identity of the compound?

1 answer:

sergij07 [2.7K]2 years ago

3 0

Answer:

CaF2

Explanation:

1 mole of CaF2 = 78.0748064 grams

78 times 3.33= 259.74

the others multiplied were nowhere near 260 grams either

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prohojiy [21]

Answer:

i can only help with 2 :( atimic mass is: 35.453 and number of electrons is:17

Explanation:

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2 years ago

a rock weighing 75.0g placed in a graduated cylinder displacing the volume from 31.4 ml to 36.5 ml what is density of the rock i

andrezito [222]

Answer:

<span>ρ≅13.0⋅g⋅m<span>L<span>−1</span></span></span> = <span>13.0⋅g⋅c<span>m<span>−3</span></span></span>

Explanation:

<span>Density=<span>MassPer unit Volume</span></span> = <span><span>75.0⋅g</span><span><span>(36.5−31.4)</span>⋅mL</span></span> <span>=??g⋅m<span>L<span>−1</span></span></span>

Note that <span>1⋅mL</span> = <span>1⋅c<span>m<span>−3</span></span></span>; these are equivalent units of volume;
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3 years ago

The normal freezing point of water is 0.00 ⁰C. What is the freezing point of a solution containing450.0 mg of ethylene glycol (M

anyanavicka [17]

Answer:

Freezing T° of solution = - 8.98°C

Explanation:

We apply Freezing point depression to solve this problem, the colligative property that has this formula:

Freezing T° of pure solvent - Freezing T° of solution = Kf . m

Kf = 1.86°C/m, this is a constant which is unique for each solvent. In this case, we are using water

m = molality (moles of solute / 1kg of solvent)

We convert the mass of solvent from g to kg

1.5 g . 1kg/1000g = 0.0015 kg

We convert the mass of solute, to moles. Firstly we make this conversion, from mg to g → 450mg . 1g/1000mg = 0.450 g

0.450 g. 1mol / 62.07g = 7.25×10⁻³ moles

Molality → 7.25×10⁻³ mol / 0.0015 kg = 4.83 m

- Freezing T° of solution = 1.86°C /m . 4.83 m - Freezing T° of pure solvent

-Freezing T° of solution = 1.86°C /m . 4.83 m - 0°C

Freezing T° of solution = - 8.98°C

8 0

2 years ago

Read 2 more answers

What could using cobalt glass be helpful to identify?<br>

satela [25.4K]

Answer:

Using cobalt glass could be helpful to identify elements that weakly emit blue and/or violet.

Explanation:

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2 years ago

HCl(aq)+NaOH(aq)→NaCl(aq)+H2O(l)

RSB [31]

Answer:

0.036 g

Explanation:

<em>0.036 g of water should be produced.</em>

From the equation of reaction, 1 mole of HCl requires 1 mole of NaOH in order to produce 1 mole of H2O.

20 mL of 0.10 M HCl contains 20/1000 x 0.10 = 0.002 moles of HCl

46 grams of NaOH contains 46/40 = 1.15 moles of NaOH

<em>It thus means that the HCl is a limiting reagent in the reaction.</em>

From the equation:

1 mole HCl will produce 1 mole of H2O.

0.002 HCl with therefore produce 0.002 x 1/1 = 0.002 mole of H2O

<em>Mass of water produced = mole x molar mass</em>

0.002 x 18 = 0.036 g.

Hence, 0.036 g of water would be produced.

8 0

3 years ago