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Lorico [155]
3 years ago
7

____ the water for 20 mins kills all microbes​

Chemistry
1 answer:
AleksandrR [38]3 years ago
8 0

Answer:

<h2>Boiling is a very simple method of water disinfection. Heating water to a high temperature, 100°C, kills most of the pathogenic organisms, particularly viruses and bacteria causing waterborne diseases. In order for boiling to be most effective, the water must boil for at least 20 minutes. </h2>

Explanation:

You might be interested in
Vanadium (V) and oxygen (O) form a series of compounds with the following compositions: Mass % V 76.10 67.98 61.42 56.02 Mass %
11Alexandr11 [23.1K]

Answer:

For every given mass of Vanadium, the relative number of oxygen atoms present or the mole ratio of Oxygen to Vanadium is:

A. 1:1

B. 3:2

C. 2:1

D. 5:2

<em>Note: The question is stated more clearly below:</em>

<em>Vanadium (V) and oxygen (O) form a series of compounds with the following compositions: Mass % V 76.10 67.98 61.42 56.02 Mass % O 23.90 32.02 38.58 43.98 Compound Mass % N 1 33.28 2 39.94.</em>

<em>What are the relative numbers of atoms of oxygen in the compounds for a given mass of vanadium?</em>

Explanation:

Number of moles in 100 g mass = % mass / molar mass

Molar mass of Vanadium, V = 51 g/mol

Molar mass of oxygen atom, O = 16 g/mol

1. Percentage mass of V and O is 76.10% and 23.90% respectively.

Number of moles of each atom;

V = 76.10/51.0 = 1.5 moles

O = 23.9/16 = 1.5 moles

Mole ratio of oxygen to vanadium = 1.5/1.5 = 1 : 1

2. Percentage mass of V and O is 67.98% and 32.02% respectively

Number of moles of each atom:

V = 67.98/51 = 1.33

O = 32.02/16 = 2

Mole ratio of oxygen to vanadium = 2/1.33 = 1.5 : 1 = 3 : 2

3. Percentage mass of V and O is 61.42% and 38.58% respectively

Number of moles of each atom:

V = 61.42/51 = 1.2

O = 38.58/16 = 2.4

Mole ratio of oxygen to vanadium = 2.4/1.2 = 2 : 1

4. Percentage mass of V and O is 56.02% and 43.98% respectively

Number of moles of each atom:

V = 56.02/51 = 1.10

O = 43.98/16 = 2.75

Mole ratio of oxygen to vanadium = 2.75/1.10 = 2.5 : 1 = 5 : 2

6 0
3 years ago
tert-Butyl alcohol is a solvent with a Kf of 9.10 ∘C/m and a freezing point of 25.5 ∘C. When 0.807 g of an unknown colorless non
Lina20 [59]

Answer:

ethylene glycol (molar mass = 62.07 g/mol).

Explanation:

  • We can solve this problem using the relation:

<em>ΔTf = Kf.m,</em>

ΔTf is the depression in the freezing point of tert-Butyl alcohol (ΔTf = freezing point of pure solvent - freezing point in presence of unknown liquid = 25.5°C - 15.3°C = 10.2°C).

Kf is the molal freezing point constant of tert-Butyl alcohol (Kf = 9.1 °C/m).

m is the molality of unknown liquid.

∵ ΔTf = Kf.m

<em>∴ m = ΔTf/Kf </em>= (10.2°C)/(9.1 °C/m) = <em>1.121 m.</em>

  • We need to calculate the molar mass of the unknown liquid:

Molality (m) is the no. of moles of solute in 1.0 kg of solvent.

∴ m = (mass/molar mass) of unknown liquid/(mass of tert-Butyl alcohol (kg))

m = 1.121 m, mass of unknown liquid = 0.807 g, mass of tert-Butyl alcohol = 11.6 g = 0.0116 kg.

<em>∴ molar mass of unknown liquid = (mass of unknown liquid)/(m)(mass of tert-Butyl alcohol (kg)) </em>= (0.807 g)/(1.121 m)(0.0116 kg) = <em>62.06 g/mol.</em>

<em></em>

  • So, the unknown liquid is:

<em>ethylene glycol (molar mass = 62.07 g/mol).</em>

3 0
3 years ago
What atomic nucleus has the fewest protons
maksim [4K]
Hydrogen-

Hydrogen is the answer because the number of protons is the atomic number.  All the elements have different atomic numbers and hydrogen has the least with an atomic number of 1.
3 0
4 years ago
So...Animals breathe in Oxygen and breathe out carbon dioxide...What spheres would this be?
ivolga24 [154]

Answer:

Animals breathe by absorbing oxygen gas from the atmosphere and releasing carbon dioxide gas back into the atmosphere from their bodies during the process. This carbon dioxide is released by the animal's cells as a waste product during cellular respiration.

Explanation:

5 0
3 years ago
The combined gas law states that
seropon [69]

Answer:

Option B. PV = nRT.

Explanation:

From the above,

C = PV / T. (1)

But, C is directly proportional to n, where R is the gas constant i.e

C & n

C = nR

Substituting the value of C into equation (1), we have:

C = PV / T

nR = PV / T

Cross multiply to express in linear form

nRT = PV

Therefore,

PV = nRT

8 0
3 years ago
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