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1 year ago

Dmitri mendeleev contribution to the periodic table.

1 answer:

8 0

In 1871, a Russian Chemist, Dimitri Mendeleev, gave a useful scheme for classification of elements. He presented the first regular periodic table in which elements of similar chemical properties were arranged in eight vertical columns called groups. The horizontal rows of table were called periods. He arranged elements in ascending order of their atomic masses and found that elements having similar chemical properties appeared at regular intervals. This observation was called Periodic Law.

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A sample of gas occupies 9.0 mL at a pressure of 500.0 mm Hg. A new volume of the same sample is at a pressure of 750.0 mm Hg.

Anuta_ua [19.1K]

<h3>Answer:</h3>

The New pressure (750 mmHg) is greater than the original pressure (500 mmHg) hence, the new volume (6.0 mL) is smaller than the original volume (9.0 mL).

<h3>Solution:</h3>

According to Boyle's Law, " <em>The Volume of a given mass of gas at constant temperature is inversely proportional to the applied Pressure</em>". Mathematically, the initial and final states of gas are given as,

P₁ V₁ = P₂ V₂ ----------- (1)

Data Given;

P₁ = 500 mmHg

V₁ = 9.0 mL

P₂ = 750 mmHg

V₂ = ??

Solving equation 1 for V₂,

V₂ = P₁ V₁ / P₂

Putting values,

V₂ = (500 mmHg × 9.0 mL) ÷ 750 mmHg

V₂ = 6.0 mL

<h3>Result:</h3>

The New pressure (750 mmHg) is greater than the original pressure (500 mmHg) hence, the new volume (6.0 mL) is smaller than the original volume (9.0 mL).

4 0

2 years ago

Read 2 more answers

A student states that an exothermic chemical reaction can transfer its heat only by convection and conduction. Which disproves t

Over [174]

b is the right answer

6 0

2 years ago

Read 2 more answers

Liquid A and liquid B form a solution that behaves ideally according to Raoult's law. The vapor pressures of the pure substances

Rama09 [41]

Answer:

Vapor pressure of solution → 151.1 Torr

Option 2.

Explanation:

Raoult's Law is relationed to colligative property about vapor pressure. A determined solute, can make, the vapor pressure of solution decreases.

ΔP = P° . Xm

where Xm is the mole fraction of solute, P° (vapor pressure of pure solvent)

and ΔP = Vapor pressure of pure solvent - Vapor pressure of solution.

In order to determine the vapor pressure of solution, we need to determine, the vapor pressure of B and A in the solution

B's pressure = P° B . Xm

When we add A to B, A works as the solute and B, as the solvent.

Vapor pressure of pure B is 135 torr. (P° B)

In order to determine, the Xm, we use the moles of A and B

Xm = 5.3 mol of B / (1.28 + 5.3) → 0.806

B's pressure = 135 Torr . 0.806 → 108.81 Torr

If mole fraction of B is 0.806, mole fraction for A (solute) will be (1 - 0.806)

A's pressure = 218 Torr . 0.194 → 42.3 Torr

Vapor pressure of solution is sum of vapor pressures of solute + solvent.

Vapor pressure of solution = 42.3 Torr + 108.81 Torr → 151.1 Torr

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2 years ago

According to markovnikov's rule of the electrophilic addition to an alkene, the electrophile, usually a proton, is more likely t

stealth61 [152]

According to markovnikov's rule of the electrophilic addition to an alkene, the electrophile, usually a proton, is more likely to add to the less-substituted carbon in a double bond.

With additional substituents present in this configuration, the intermediate carbocation is stabilised by being located on the more-substituted carbon.

The nucleophile will then end up in a double bond on the more-substituted carbon in a reaction that follows Markovnikov's rule.The outcome of some addition reactions is described by Markovnikov's rule or Markownikoff's rule in organic chemistry. Vladimir Markovnikov, a Russian scientist, created the rule in 1870.

To learn more about Markovnikov's rule

brainly.com/question/14529644

#SPJ4

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1 year ago

Vinegar produces carbon dioxide gas when combined with baking soda. Physical or chemical property?

Bas_tet [7]

Answer:

it's a chemical property

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2 years ago