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2 years ago

Elements and compounds are usually more dense in their solid than in their

Chemistry

1 answer:

sladkih [1.3K]2 years ago

8 0

Explanation:

The molecules in water is more tightly packed than in ice, so water has greater density than ice.

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You are running a rather large scale reaction where you prepare the grignard reagent phenylmagnesium bromide by reacting 210.14

almond37 [142]

Answer:

We would expect to form 7.35 moles of grignard reagent.

Explanation:

Step 1: Data given

Mass of magnesium = 210.14 grams

Volume bromobenzene = 772 mL

Density of bromobenzene = 1.495 g/mL

Molar mass of Mg = 24.3 g/mol

Molar mass of bromobenzene = 157.01 g/mol

Step 2: The balanced equation

C6H5Br + Mg ⇒ C6H5MgBr

Step 3: Calculate mass of bromobenzene

Mass bromobenzene = density bromobenzene * volume

Mass bromobenzene = 1.495 g/mL * 772 mL

Mass bromobenzene = 1154.14 grams

Step 4: Calculate number of moles bromobenzene

Moles bromobenzene = mass bromobenzene / molar mass bromobenzene

Moles bromobenzene = 1154.14g / 157.01 g/mol

Moles bromobenzene = 7.35 moles

Step 5: Calculate moles of Mg

Moles Mg = 210.14 grams /24.3 g/mol

Moles Mg = 8.65 moles

Step 6: The limiting reactant

The mole ratio is 1:1 So the bromobenzene has the smallest amount of moles, so it's the limiting reactant. It will be completely consumed ( 7.35 moles). Magnesium is in excess, There will react 7.35 moles. There will remain 8.65 - 7.35 = 1.30 moles

Step 7: Calculate moles of phenylmagnesium bromide

For 1 mole of bromobenzene, we need 1 mole of Mg to produce 1 mole of phenylmagnesium bromide

For 7.35 moles bromobenzene, we have 7.35 moles phenylmagnesium bromide

We would expect to form 7.35 moles of grignard reagent.

5 0

2 years ago

Which of the following is not a statement of Dalton's atomic theory of matter?a. Elements are made of atomsb. Atoms of a given e

Alona [7]

Answer:

c. The atoms of one element can be identical to the atoms of another element.

Explanation:

Which of the following is not a statement of Dalton's atomic theory of matter?

a. Elements are made of atoms. TRUE. An atom is the smallest particle of a chemical element that can exist.

b. Atoms of a given element are identical. TRUE. The only slight difference is in the mass of isotopes.

c. The atoms of one element can be identical to the atoms of another element. FALSE. The atoms of different elements are different from one to another.

d. A given compound always has the same number and kinds of atoms. TRUE. This is known as Dalton's law of constant composition.

3 0

3 years ago

A chemist must prepare of 800.0 ml potassium hydroxide solution with a pH of 13.00 at 25Â°.

ArbitrLikvidat [17]

Answer:

4.48 grams is the mass of potassium hydroxide that the chemist must weigh out in the second step.

Explanation:

The pH of the solution = 13.00

pH + pOH = 14

pOH = 14 - pH = 14 - 13.00 = 1.00

$pOH=-\log[OH^-]$

$1.00=-\log[OH^-]$

$[OH^-]=10^{-1.00} M=0.100 M$

$KOH(aq)\rightarrow K^+(aq)+OH^-(aq)$

$[KOH]=[OH^-]=[K^+]=0.100 M$

Molariy of the KOH = 0.100 M

Volume of the KOH solution = 800 mL= 0.800 L

1 mL = 0.001 L

Moles of KOH = n

$Molarity=\frac{Moles}{Volume(L)}$

$0.100 M=\frac{n}{0.800 L}$

n = 0.0800 mol

Mass of 0.0800 moles of KOH :

0.0800 mol × 56 g/mol = 4.48 g

4.48 grams is the mass of potassium hydroxide that the chemist must weigh out in the second step.

4 0

3 years ago

What functional group is aspartic acid

Westkost [7]

The functional group of aspartic acid is -COOH.

8 0

3 years ago

How has the Chesapeake Bay watershed changed over time?

Alisiya [41]

Answer:

The Chesapeake Bay watershed continues to develop as population in the region grows. Development and urbanization at the cost of natural landscapes can lead to increased pollution of nutrients and sediment to the Bay, especially from stormwater runoff.

Explanation:

5 0

2 years ago