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3 years ago

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Chemistry

1 answer:

Leya [2.2K]3 years ago

3 0

Answer:

E. a small yellow ball that represents the Sun

Explanation:

key word on the question, 'physical'

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The balanced equation for combustion in an acetylene torch is shown below: 2C2H2 + 5O2 → 4CO2 + 2H2O The acetylene tank contains

andriy [413]

Answer: 67.2 moles

Explanation: $2C_2H5+5O_2\rightarrow 4CO_2+2H_2O$

According to the given balanced equation, 2 moles of acetylene $C_2H_2$ combine with 5 moles of oxygen $O_2$ to produce 4 moles of carbon dioxide $CO_2$ .

Thus if 2 moles of acetylene $C_2H_2$ combine with = 5 moles of oxygen $O_2$

35 moles of acetylene $C_2H_2$ combine with= $\frac{5}{2}\times {35}=87.5$ moles of oxygen $O_2$

But as only 84 moles of oxygen are available, acetylene is not a limiting reagent.

5 moles of oxygen $O_2$ reacts with = 2 moles of acetylene $C_2H_2$

84 moles of oxygen $O_2$ reacts with= $\frac{2}{5}\times {84}=33.6$ moles of acetylene $C_2H_2$

Thus Oxygen is the limiting reagent as it limits the formation of products. Acetylene is excess reagent as it is present in excess.

2 moles of acetylene $C_2H_2$ produce= 4 moles of carbon dioxide $CO_2$ .

33.6 moles of acetylene $C_2H_2$ produce= $\frac{4}{2}\times {33.6}=67.2$ moles of of carbon dioxide $CO_2$ .

8 0

3 years ago

Read 2 more answers

Osmosis is the process responsible for carrying nutrients and water from groundwater supplies to the upper parts of trees. The o

Nady [450]

Answer:

0.825 M

Explanation:

The osmotic pressure is a colligative property, that can be calculated using the following expression.

π = M × R × T

where,

π is the osmotic pressure

M is the molarity

R is the ideal gas constant

T is the absolute temperature (24°C + 273 = 297 K)

M = π / R × T = 20.1 atm / (0.08206 atm.L/mol.K) × 297 K = 0.825 M

5 0

3 years ago

Pls help 8th grade k12

I am Lyosha [343]

Look it up online you will find it

6 0

2 years ago

In recrystallization from boiling water of benzoic acid contaminated with acetanilide, you begin with an impure sample of 5 gram

kherson [118]

This question is incomplete, the complete question is;

In recrystallization from boiling water of benzoic acid contaminated with acetanilide, you begin with an impure sample of 5 grams. If the % composition of the acetanilide impurity in the sample is 6.3 %, what is the minimum amount in mL of solvent (water) required for the recrystallization

Compound Solubility in water at 25°C Solubility in water at 100°C

Benzoic Acid 0.34 g/100mL 5.6 g/100mL

Acetanilide 0.53 g/100mL 5.5 g/100mL

Answer:

The minimum amount in mL of solvent (water) required for the recrystallization is 91 mL

Explanation:

Given the data in the question;

mass of sample = 5 g

percentage composition of the acetanilide impurity = 6.3%

mass of the acetanilide in impure sample will be;

⇒ 6.3% × 5 g = 0.315 g

Mass of benzoic acid in impure sample;

⇒ 5 g - 0.315 g = 4.685 g

now, solubility in water at 100°C for benzoic acid = 5.6 g/100mL

hence 4.685 g of benzoic acid is soluble in x mL

x = [ 100 mL × 4.685 g ] / 5.6 g

x = 83.66 ≈ 84 mL

Also, solubility in water at 100°C for acetanilide = 5.5 g/100mL

hence 0.315 g of benzoic acid is soluble in x mL

x = [ 100 mL × 0.315 g ] / 5.5 g

x = 5.727 ≈ 6 mL

So, the minimum amount in mL of solvent (water) required for the recrystallization will be;

⇒ 85 mL + 6 mL = 91 mL

The minimum amount in mL of solvent (water) required for the recrystallization is 91 mL

5 0

3 years ago

Consider the following statements about weeding and identify the incorrect one.

dolphi86 [110]

Answer:

b) Weeding is the process of growing weed

Explanation:

Wedding is an agricultural process carried out to ensure maximum you won't do. It is the process by which weeds i.e. unwanted plants are removed.

As rightly stated in the question;

- Weeding is either done by manual means e.g Cutlasses or use of weedicides, which are chemicals.

- Weeding is best done during tiling operations.

The incorrect option is that "Weeding is the process of growing weed" rather it is a process of removing weed.

4 0

3 years ago