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3 years ago

5

Samira has two pens. She wants to know which pen was used to write a note. She labels her pens A and B. She puts a sample of ink

from each pen onto some chromatography paper. Then she puts a sample of the ink from the note onto the chromatography paper.

1 answer:

Ann [662]3 years ago

8 0

Answer:

b

Explanation:

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¿Cómo se llama el grupo IIA de la tabla periódica?

Verdich [7]

Answer:

los metales alcalinotérreos: berilio (Be), magnesio (Mg), calcio (Ca), estroncio (Sr), bario (Ba) y radio (Ra).

o simplemente llamado grupo 2A

Explanation:

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3 years ago

4 moles of hydrogen react with 5 moles of oxygen to form water, identify the excess reagent?

Fynjy0 [20]

Answer:

Excess Reagent = oxygen

Explanation:

Limiting reagent: The substance that is totally consumed when the reaction is completed.

Excess reagent: The substance left after the limiting reagent is consumed completely

The balanced chemical equation for formation of water is as follow:

$2H_{2}+O_{2}\rightarrow 2H_{2}O$

This means when 2 moles of hydrogen reacts with 1 mole of oxygen, 2 moles of water is produced.

Hence the ratio in which hydrogen and oxygen gas reacts is 2:1

Now if 2 mole hydrogen require 1 mole of oxygen ,then 4 mole hydrogen need 2 mole of oxygen.

$H_{2}:O_{2}=2:1$

or

$H_{2}:O_{2}=4:2$

Here 5 mole of oxygen is reacting but only 2 mole is required .

Oxygen is in excess.

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3 years ago

Description of horizon a

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I like that game Forza horizon

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3 years ago

What type of energy does water gain as it sits in the sun?

Sveta_85 [38]

Answer:

A. Heat energy

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3 years ago

Properties of iron, barium, and phosphorus. Explain why nails are made of iron but they are never made of barium or phosphorus.

bearhunter [10]

Nails are made up of iron not of phosphorus and barium.

As both phosphorous and barium are relatively weaker than iron ,phosphorus breaks easily and barium is also fairly weak. Iron nails are already also not that strong, but their weight and strength are sufficient.

So the nails are made up of iron.

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