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natima [27]
3 years ago
13

Twenty students were surveyed to find out how many hours of TV they watch during a school week. The results are shown to the rig

ht. Answer the following questions and round your answers to the nearest half hour. The mean of the data is ____ hours.
Chemistry
2 answers:
natulia [17]3 years ago
8 0

Answer: 4.5

Explanation:

Just did it

alexandr402 [8]3 years ago
3 0

Answer:

5 Hours

Explanation: I just wanted to save your time and i added all the hours up divided by 20 which i got 4.95 then rounded up to 5.

You might be interested in
How will vinegar slow down the break down of an apple?
Gennadij [26K]

Answer:

Many people take apple cider vinegar before protein-heavy meals to improve digestion. The theory is that apple cider vinegar increases the acidity of your stomach, which helps your body create more pepsin, the enzyme that breaks down protein

5 0
3 years ago
When a 0.245-g sample of benzoic acid is combusted in a bomb calorimeter, the temperature rises 1.643 ∘C . When a 0.260-g sample
sveticcg [70]

Answer:

The heat of combustion per moles of caffeine is 4220 kJ/mol

Explanation:

Step 1: Data given

⇒ When  benzoic acid sample of 0.245 grams is burned the temperature rise is 1.643 °C

⇒ When 0.260 gram of caffeine is burned, the temperature rise is 1.436 °C

⇒ Heat of combustion of benzoic acid = 26.38 kJ/g

<u>Step 2:</u> Calculate the heat released: for combustion of benzoic acid

0.245 g benzoic acid *  26.38 kJ/g = 6.4631 kJ

<u>Step 3</u>: Calculate the heat capacity of the calorimeter:

c = Q/ΔT

Q = 6.4631 kJ   / 1.643°C = 3.934 kJ/ °C

<u>Step 4:</u> Calculate moles of a 0.260 g sample of caffeine:

Moles caffeine = Mass caffeine / Molar mass caffeine

0.260 grams/ 194.19 g/mol  = 0.0013389 moles

Step 5: Calculate heat released: for combustion of caffeine

Q = c * ΔT

Q = 3.934 kJ/°C * 1.436 °C = 5.65 kJ

Step 6: Calculate the heat of combustion per mole of caffeine  

5.65 kJ  /  0.0013389 moles = 4219.9 kJ/mol  ≈ 4220 kJ/mol

The heat of combustion per moles of caffeine is 4220 kJ/mol

4 0
4 years ago
2 drops of vinegar &amp; 2 drops ammonia solution or not​
Naya [18.7K]

Answer:

No, this is false because we know about the law that says if you add two things together you are adding the masses together, 2 drops of vinegar and 2 drops of ammonia would equal four drops of solution not two

Hope this helps!!

Explanation:

5 0
3 years ago
The solubility of oxygen gas in water at 40 ∘c is 1.0 mmol/l of solution. What is this concentration in units of mole fraction?
juin [17]

The formula for mole fraction is:

mole fraction of solute = \frac{number of moles of solute}{total number of moles of solution}    -(1)

The solubility of oxygen gas = 1.0 mmol/L  (given)

1.0 mmol/L means 1.0 mmol are present in 1 L.

Converting mmol to mol:

1.00 mmol\times \frac{1 mol}{1000 mmol} = 0.001 mol

So, moles of oxygen = 0.001 mol

For moles of water:

1 L of water = 1000 mL of water

Since, the density of water is 1.0 g/mL.

Density = \frac{mass}{volume}

Mass = 1.0 g/ml\times 1000 mL = 1000 g

So, the mass of water is 1000 g.

Molar mass of water = 18 g/mol.

Number of moles of water = \frac{1000 g}{18 g/mol} = 55.55 mol

Substituting the values in formula (1):

mole fraction = \frac{0.001}{55.55+0.001}

mole fraction = 1.8\times 10^{-5}

Hence, the mole fraction is 1.8\times 10^{-5}.

7 0
3 years ago
4. Which of the following NOT TRUE about real gas
Semenov [28]

Answer:

The answer is D.

Explanation:

Intermolecular force are negligible

When the distance between molecules decrease,

the attraction or repulsion become greater

7 0
2 years ago
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