Explanation:

Explanation:

The total number of electrons in $18$ ml of water  is 6.02×10²⁴. Since, the density is $1$ g/mL, $18$ ml of water corresponds to $18$ g or $1$ mole as the molecular weight of water is $18$ g/mole.

 $1$ mole of water contains $10$ moles of electrons, $8$ moles of electrons from $O$ and $2$ moles of electrons from $H$.  

$1$ mole of electrons corresponds to Avogadro’s number which is 6.02×10²³ $\times$ $10$ moles of electrons will correspond to 6.02×10²⁴ electrons.

Explanation:

2 H₂O₂ → 2 H₂O + O₂

Moles of H₂O₂ in 0.68 g:
Molar mass of H₂O₂ = 34 g/mol
n(H₂O₂) = 0.68 / 34 = 0.02 mol

From the equation,
2 mol H₂O₂ → 1 mol O₂
So 0.02 mol H₂O₂ → 0.02 / 2
= 0.01 mol O₂

Volume of 0.01 mol O₂ at STP:
1 mol gas at STP = 22.4 L
= 22400 mL
Volume = 0.01 × 22.4 L
= 0.224 L
= 224 mL

So, the volume of O₂ evolved at STP = 224 mL.

Given

• Density of water (ρ) = 1g/cm³
• Molar mass of water (M) = 18 g/mol

∴ Molar volume (Vm) = M/ρ

V_m = 18 cm³/mol

∴ Volume of 1 molecule of water = V_m/N_A

Where N_A is Avogadro number

Volume of 1 molecule of water = 18/(6.022 × 10²³)

Volume of 1 molecule of water = 2.989 × 10^-23 ≈ 3 × 10^-23.

The mass of 0.3 moles of ammonia can be calculated using the following steps:

The molar mass of ammonia is 17 grams/mole. Therefore, the mass of 0.3 moles of ammonia is (0.3 moles * 17 grams/mole) = 5.1 grams.

One mole H2 bas occupy 24-liter volume at RTP hence 0.25 moles of H2 occupy.                           
0.25×24L. =6 Liter

NOTE: 
Question Me RTP he STP hota then Answer 5.6 hota

mass in gram/molar mass

all these formula are used for calculating number of moles.

number of moles= mass in grams/molar mass

Because 1litre=1kg
1kg water will have mass 1000 grams so
Moles=mass/molar mass
=1000/18 = 55.5 moles

C(s)+O2(g)➡️CO2.One mole of CO2 requires 32 gram of O2 so 0.25 moles will require 8g of O2

At RTP one mole of each gas occupies 24dm3 of volume.

1 mole= 24
1/4 moles = x
Cross Multiplication
so 
x=24/4
x=6

Explanation:

Statement C is incorrect because, by definition, one mole of any substance contains the same number of particles (Avogadro’s number), regardless of what the substance is. The mass of that mole, however, will be different for different substances. 

Explanation:

At STP , volume of 1 mole $=$ 22.7 L

1 m³ has 1000 L
Then, n (no. of moles) in 1 m³ = 1000 / 22.7 = $44.642mole$

The ratio of no. of moles of reactants taking part and the no. of moles of product formed is called mole ratio

Explanation:

The molar mass of sodium (Na) is its atomic mass expressed in grams per mole. The atomic mass of sodium is approximately 23 g/mol.
Mass of one mole of sodium=23 g

22,414 cm³ of an ideal gas is approximately equal to 1 mole at standard temperature and pressure (STP).

Explanation:

. 

The ratio of no. of moles of reactants taking part and the no. of moles of product formed is called mole ratio

1 mole of Na=23g

Explanation:

A fundamental concept in chemistry, derived from the ideal gas law (PV = nRT) and Avogadro’s law, is that one mole of any ideal gas at standard temperature 0C or273.15 K occupies a standard molar volume of approximately 22.4 liters or more precisely22.414L

Explanation:

Explanation:

This is due to the definition of a mole and Avogadro’s number: one mole of any substance contains a fixed number of constituent particles (molecules, in this case)

EXPLANATION:

no. of atoms of oxygen= n ×NA× no. of atoms in formula

no. of atoms of oxygen = 0.5 × 6.023 × 10^23 ×9

no. of atoms of oxygen= 27.09 × 10^23

no. of atoms of oxygen=2.7 × 10^24

EXPLANATION:

no. of moles= volume in dm3/ molar volume

volume in dm3= no. of moles × molar volume

first find no. of moles = n= mass in grams/ molar mass

n=2.8/28

n=0.1 moles 

now putting in formula

volume in dm3= n × molar volume

volume in dm3= 0.1 × 22.4

volume in dm3= 2.24 dm3

EXPLANATION:

one mole of C-12=12g 

and 12 g= 0.012 kg

EXPLANATION:

No. of moles= n= mass in grams/ molar mass

n= 75/58= 1.29

EXPLANATION:

as one mole is a constant number so number of molecules is same for all of them 

the atomic mass, molecular mass, formula mass or ionic mass expressed in grams is called as mole

one gram atom of an element contains the same number of atoms, which is Avogadro’s number (approximately 6.022 × 10²³ atoms). This is true for any element, as one gram atom refers to the amount of an element that equals its atomic mass in grams, ensuring it contains the same number of atoms.

1 mole of oxygen atoms contains:

• 16 grams of oxygen (since the atomic mass of oxygen is 16 g/mol).
• 6.022 × 10²³ atoms (Avogadro’s number).

the amount of a substance which contains avogadro’s number of particles is called as mole

mass in grams of one mole of a substance is called as molar mass

The term molar mass is also used to refer to the mass of one mole of any substance, including moles, atoms, and molecules. Molar mass is typically expressed in grams per mole (g/mol) and provides a convenient way to convert between the mass of a substance and the amount of substance in moles.

both statements are correct.

The equation
𝑛=mass in grams/molar mass
​
calculates the number of moles (𝑛) of a substance based on its mass and molar mass.

The equation
mass in grams=n×molar mass calculates the mass of a substance when you know the number of moles and the molar mass.

Molar Mass of CaCo3=100 g/mol
mole=Mass/Molar Mass
0.5=mass/100
mass=50 g

one mole of any gas at standard temp and pressure occupies a volume of 22.4 dm³ this is called as molar volume

molar volume of a gas at STP is equals to 22.4dm³

RTP refers to temperature of 25°C (298K) and pressure of 1 atmosphere. The molar volume of any gas at RTP is 24.0 dm³ ( 24.0 L).