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2 years ago

What is the molecular formula of a compound with an empirical formula P2O5 and a gram-molecular mass of 284 grams? And why?

1 answer:

5 0

I really don’t know but

Phosphorus pentoxide is a white solid which does not have any distinct odour. The chemical formula of this compound is P4O10. However, it is named after its empirical formula, which is P2O5. The molar mass of phosphorus pentoxide corresponds to 283.9 g/mol.

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Which of the following is part of the central nervous system?

OLga [1]

The brain is part of the central nervous system.

Nerves and sensors are part of the peripheral nervous system. Only the brain and spinal cord make the central nervous system.

3 0

2 years ago

Read 2 more answers

What expression approximates the volume of O2 consumed, measure at STP, when 55 g of Al reacts completely with excess O2?2 Al(s)

nikdorinn [45]

Answer : The volume of $O_2$ consumed are, $0.75\times 2\times 22.4$ L.

Explanation :

The balanced chemical reaction will be:

$4Al(s)+3O_2(g)\rightarrow 2Al_2O_3(s)$

First we have to calculate the moles of Al.

$\text{Moles of }Al=\frac{\text{Mass of }Al}{\text{Molar mass of }Al}$

Molar mass of Al = 27 g/mole

$\text{Moles of }Al=\frac{55g}{27g/mol}=2mole$

Now we have to calculate the moles of $O_2$ .

From the reaction we conclude that,

As, 4 mole of Al react with 3 moles of $O_2$

So, 2 mole of Al react with $\frac{3}{4}\times 2=0.75\times 2$ moles of $O_2$

Now we have to calculate the volume of $O_2$ consumed.

As we know that, 1 mole of substance occupies 22.4 liter volume of gas.

As, 1 mole of $O_2$ occupies 22.4 liter volume of $O_2$ gas

So, $0.75\times 2$ mole of $O_2$ occupies $0.75\times 2\times 22.4$ liter volume of $O_2$ gas

Therefore, the volume of $O_2$ consumed are, $0.75\times 2\times 22.4$ L.

3 0

3 years ago

The Earth rotates about its axis from west to east. What piece of evidence about the Moon can we use to support this statement?

Debora [2.8K]

The Earth's rotation has no relation to the phases of the moon.
Like everything else in the sky, the moon rises in the east just like the stars, planets, and the sun.

8 0

3 years ago

Read 2 more answers

whoch of the following statments doesnt describe the structure of a atowhich of the following do not describe the structure of a

ra1l [238]

Answer : The incorrect option is, The most of the mass of the atom comes from the electron cloud.

Explanation :

There are three basic particles of an atom which are neutrons, protons and electrons.

The nucleus which is present in the center of an atom that contains the neutrons and the protons. The protons are positively charged and neutrons has no charge.

The outer region of an atom contains the electrons and the electrons are negatively charged.

As per given options, the statement which is the most of the mass of the atom comes from the electron cloud is incorrect statement because the most of the mass comes from the nucleus in which protons and neutrons are present.

5 0

2 years ago

The freezing point of ethanol, CH3CH2OH, is -117.300 °C at 1 atmosphere. Kf(ethanol) = 1.99 °C/m

MAXImum [283]

Answer : The molecular weight of this compound is 891.10 g/mol

Explanation : Given,

Mass of compound = 12.70 g

Mass of ethanol = 216.5 g

Formula used :

$\Delta T_f=i\times K_f\times m\\\\T_f^o-T_f=i\times T_f\times\frac{\text{Mass of compound}\times 1000}{\text{Molar mass of compound}\times \text{Mass of ethanol}}$