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Eva8 [605]
3 years ago
11

A 2.050×10−2 MM solution of glycerol (C3H8O3C3H8O3) in water is at 20.0∘C∘C. The sample was created by dissolving a sample of C3

H8O3C3H8O3 in water and then bringing the volume up to 1.000 LL. It was determined that the volume of water needed to do this was 999.1 mLmL . The density of water at 20.0∘C∘C is 0.9982 g/mLg/mL. Part A Calculate the molality of the glycerol solution. Express your answer to four significant figures and include the appropriate units.
Chemistry
1 answer:
blondinia [14]3 years ago
5 0

Answer:

[Glycerol] = 0.0205 mol/kg

Explanation:

Molality means concentration. This sort of concentration indicated the moles of solute which are contained in 1kg of solvent.

We start from molarity which are the moles of solute, that are contained in 1L of solution.

2.05×10⁻² mol/L are contained in 1 L of solution.

We must assume, that volume of solvent is 999.1 mL so let's determine the mass of solvent, by density

999.1 mL . 0.9982 g/7mL = 997.3 g

For molality we need mass in kg, so let's convert the mass of solvent

997.3 g . 1kg /1000g = 0.9973 kg.

Molality → mol/kg → 2.05×10⁻² mol / 0.9973 kg = 0.0205 m

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What is the mass of 22.4L of H2 at stp
bazaltina [42]

Answer:

2.02 g H₂

General Formulas and Concepts:

<u>Chemistry - Atomic Structure</u>

  • Reading a Periodic Table
  • Using Dimensional Analysis
  • STP (Standard Conditions for Temperature and Pressure) = 22.4 L per mole at 1 atm, 273 K

Explanation:

<u>Step 1: Define</u>

22.4 L H₂ at STP

<u>Step 2: Identify Conversions</u>

STP - 22.4 L / mol

Molar Mass of H - 1.01 g/mol

Molar Mass of H₂ - 2(1.01) = 2.02 g/mol

<u />

<u>Step 3: Convert</u>

<u />22.4 \ L \ H_2(\frac{1 \ mol \ H_2}{22.4 \ L \ H_2} )(\frac{2.02 \ g \ H_2}{1 \ mol \ H_2} ) = 2.02 g H₂

5 0
2 years ago
Identify each definition that applies to the compound in red. Check all that apply.
Dvinal [7]

Answer:it’s D Brønsted-Lowry base

Explanation:

4 0
3 years ago
Which balanced equation represents a redox reaction?
nlexa [21]

Answer: option (3) CuO + CO ⇄ Cu + CO₂


Explanation:


1) A redox reaction is an oxidation-reduction reaction.


2) An oxidation-reduction reaction is one in which at least one species is oxidized and other (or others) is reduced.


3) Oxidation is the increase on the oxidation number, which occurs by releasing electrons.


4) Reduction is the decrease of the oxidation number, which occurs by gaining electrons.


5) By looking at the oxidation numbers of the reactants and the products you can tell whether a reaction is a redox one.


6) There are some rules to calculate the oxidation states which you need to handle to determine the oxidation states of the atoms in any chemical formula.


7) The main rule that you can use at a glance is if an element is alone in one side of the equation and is bonded to other kind of atom in the other side.


That is because the rule states that for any element that is not combined with other element its oxidation state is 0.


In this case, you can apply that rule to the equation of the choice number (3). In that, you can see that Cu is pure which as per the mentioned rule means that its oxidation state is 0.


As Cu is combined with O, CuO, in the reactant side of the chemical equation, then its oxidation number is not 0. Indeed, the rule is that in the formula CuO the oxidation states of Cu and O add up 0, and since the oxidation number of O is 2-, the oxidation number of Cu is 2+.


Therefore, having Cu changed its oxidation state from 2+ to 0, it was reduced, and this is a redox reaction.


Of course other atoms had to be oxidized. It was C whose oxidation state went from 2+ in CO to 4+ in CO₂.

7 0
3 years ago
Read 2 more answers
When a sample is heated water is observed at the top of the tube. The compound melts and changes color. Te residue is not entire
harkovskaia [24]

Answer:

hydrate

Explanation:

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7 0
3 years ago
For each reaction, identify the element that gets reduced and the element that gets oxidized. 2 AgCl + Zn ⟶ 2 Ag + ZnCl 2 2AgCl+
Mnenie [13.5K]

Answer:

Explanation:

Oxidation:

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Reduction:

Reduction involve the gain of electron and oxidation number is decreased.

Oxidizing agents:

Oxidizing agents oxidize the other elements and itself gets reduced.

Reducing agents:

Reducing agents reduced the other element are it self gets oxidized.

Consider the following reaction:

2AgCl + Zn  → 2Ag + ZnCl₂

In this reaction oxidation state of Zn on left side is 0 while on right side +2 so it gets oxidized and oxidation state of Ag on left side is +1 and on right side 0 so it get reduced.

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In this reaction oxidation state of nitrogen on left side is -3 while on right side 0 so it gets oxidized and oxidation state of oxygen on left side is 0 and on right side -2 so it get reduced.

Fe₂O₃ +  2Al  →   Al₂O₃ +  2Fe

In this reaction oxidation state of iron on left side is +3 while on right side 0 so it gets reduced and oxidation state of Al on left side is 0 and on right side +3 so it get oxidized.

4 0
3 years ago
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