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3 years ago

Which of the following best defines one mole of a substance?

Chemistry

1 answer:

AlexFokin [52]3 years ago

4 0

Answer: D. Amount of substance present in Avogadro‘s number of particles of the substance

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 Liters at STP, contains avogadro's number $6.023\times 10^{23}$ of particles and weighs equal to the molecular mass of that substance.

A mole is defined as the amount of substance that contains Avogardro number of the substance. Avogadro's number is given by $6.022\times 10^{23}$ .

$1mole=6.022\times 10^{23}$ particles

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Balance the following chemical equation: C2H60+02 → CO2 + H20

pantera1 [17]

Answer:

Explain: In order to balance the chemical equation, you need to make sure the number of atoms of each element on the reactant side is equal to the number of atoms of each element on the product side. In order make both sides equal, you will need to multiply the number of atoms in each element until both sides are equal.

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3 years ago

Popeye wants to make a dilute spinach solution for Sweetpea's bottle. How much 3.0 M spinach solution should he add to the 500.0

Lynna [10]

Answer : The volume of 3.0 M spinach solution added should be, 50 mL

Explanation :

Formula used :

$M_1V_1=M_2V_2$

where,

$M_1\text{ and }V_1$ are the initial molarity and volume of spinach solution.

$M_2\text{ and }V_2$ are the final molarity and volume of diluted spinach solution.

We are given:

$M_1=3.0M\\V_1=?\\M_2=0.30M\\V_2=500.0mL$

Now put all the given values in above equation, we get:

$3.0M\times V_1=0.30M\times 500.0mL\\\\V_1=50mL$

Hence, the volume of 3.0 M spinach solution added should be, 50 mL

8 0

3 years ago

1.How are volcanic soils important?

Paul [167]

Answer:

Soil provides nutrients, water, and minerals for plants and trees, stores carbon, and is home to billions of insects, small animals, bacteria, and many other microorganisms.

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2 years ago

formic acid buffer containing 0.50 M HCOOH and 0.50 M HCOONa has a pH of 3.77. What will the pH be after 0.010 mol of NaOH has b

HACTEHA [7]

Answer:

pH = 3.95

Explanation:

It is possible to calculate the pH of a buffer using H-H equation.

pH = pka + log₁₀ [HCOONa] / [HCOOH]

If concentration of [HCOONa] = [HCOOH] = 0.50M and pH = 3.77:

3.77 = pka + log₁₀ [0.50] / [0.50]

3.77 = pka

Knowing pKa, the NaOH reacts with HCOOH, thus:

HCOOH + NaOH → HCOONa + H₂O

That means the NaOH you add reacts with HCOOH producing more HCOONa.

Initial moles of 100.0mL = 0.1000L:

[HCOOH] = (0.50mol / L) ₓ 0.1000L = 0.0500moles HCOOH

[HCOONa] = (0.50mol / L) ₓ 0.1000L = 0.0500moles HCOONa

After the reaction, moles of each species is:

0.0500moles HCOOH - 0.010 moles NaOH (Moles added of NaOH) = 0.0400 moles HCOOH

0.0500moles HCOONa + 0.010 moles NaOH (Moles added of NaOH) = 0.0600 moles HCOONa

With these moles of the buffer, you can calculate pH:

pH = 3.77 + log₁₀ [0.0600] / [0.0400]

3 0

3 years ago

Suppose a solution is described as concentrated. Which of the following statements can be concluded? Select the correct answer b

Novosadov [1.4K]

Answer:

last option: none of the above.

Explanation:

Describing a solution as concentrated tells that the solution has a relative large concentration, but it is a qualitative description, not a quantitative one, so this does not tell really how concentrated the solution is. This is, the term concentrated is a kind of vague; it just lets you know that the solution is not very diluted, but, as said initially, that there is a relative large amount (concentration) of solute.

One conclusion, of course, is that the solute is soluble: else the solution were not concentrated.

On the other hand, the terms saturated and supersaturated to define a solution are specific.

A saturated solution has all the solute that certain amount of solvent can contain, at a given temperature. A supersaturated solution has more solute dissolved than the saturated solution at the same temperature; superstaturation is a very unstable condition.

From above, there is no way that you can conclude whether a solution is supersaturated or not from the statement that a solution is concentrated, so the answer is none of the above.

5 0

3 years ago