Molecular Mass

The molecular mass of sodium chloride (NaCl) can be calculated by adding the atomic masses of sodium (Na) and chlorine (Cl). Sodium has an atomic mass of approximately 22.99 g/mol, and chlorine has an atomic mass of about 35.45 g/mol. Therefore, the molecular mass of NaCl is approximately 58.44 g/mol.

The molecular mass of sulfuric acid (H₂SO₄) can be calculated by summing the atomic masses of its constituent elements: hydrogen (H), sulfur (S), and oxygen (O). Hydrogen has an atomic mass of approximately 1 amu, sulfur about 32 amu, and oxygen around 16 amu. Therefore, the molecular mass of H₂SO₄ is (2 × 1) + 32 + (4 × 16) = 98 amu.

H₂O (water) has a lower relative molecular mass than CS₂ (carbon disulfide) because the molecular mass of H₂O is approximately 18 g/mol (composed of two hydrogen atoms and one oxygen atom), while CS₂ has a molecular mass of about 76 g/mol (comprising one carbon atom and two sulfur atoms). The difference in the number and mass of the constituent atoms results in H₂O having a significantly lower molecular weight compared to CS₂.

To determine the moles of H₂ produced from the reaction between magnesium (Mg) and sulfuric acid (H₂SO₄), we start with the balanced chemical equation:

[ \text{Mg} + \text{H}_2\text{SO}_4 \rightarrow \text{MgSO}_4 + \text{H}_2 ]

From the equation, 1 mole of Mg produces 1 mole of H₂. The molar mass of Mg is approximately 24.31 g/mol.

Given 230 mg of Mg (or 0.230 g), the moles of Mg are calculated as follows:

[ \text{Moles of Mg} = \frac{0.230 , \text{g}}{24.31 , \text{g/mol}} \approx 0.00946 , \text{moles} ]

Thus, 0.00946 moles of Mg will produce approximately 0.00946 moles of H₂.

To determine the empirical formula, first find the simplest whole number ratio of the moles of each element. In this case, you have 0.04 moles of sodium (Na), 0.04 moles of sulfur (S), and 0.06 moles of oxygen (O). Divide each amount by the smallest number of moles, which is 0.04: Na = 1, S = 1, and O = 1.5. To convert to whole numbers, multiply the ratios by 2, resulting in Na₂S₂O₃ as the empirical formula.

Using moles instead of mass in an empirical formula allows for a standardized way to express the ratio of elements in a compound. Moles provide a direct measure of the number of particles (atoms or molecules), enabling a clearer understanding of the relative proportions of elements. This approach simplifies calculations and comparisons across different substances, making it easier to determine the simplest whole-number ratio of the elements. Additionally, using moles accounts for differences in atomic mass, ensuring accurate representation of the chemical composition.

First write down the BALANCED reaction eq'n.

Octane + oxygen = Water + Carbon Dioxide.

2CH3(CH2)6CH3 + 25O2 = 18H2O + 16CO2

The molar ratios are 2:25 :: 18:16

So '2' moles of octane produces 18 moles of water.

So by equivlance

0.468 : x :: 2 : 18

Algebraically rearrgange

x = (0.468/2) X 18 =>

x = 0.234 x 18 = >

x = 4.212 moles water produces.

To find the mass of 9.15 × 10²⁴ molecules of methanol (CH₃OH), we first need to determine the molar mass of methanol, which is approximately 32.04 g/mol. Using Avogadro's number (6.022 × 10²³ molecules/mol), we can convert the number of molecules to moles: ( n = \frac{9.15 \times 10^{24}}{6.022 \times 10^{23}} \approx 15.19 ) moles. Finally, we calculate the mass: ( \text{mass} = n \times \text{molar mass} = 15.19 , \text{mol} \times 32.04 , \text{g/mol} \approx 486.4 , \text{g} ).

how many moles are represented by 1.51 x 10^24 atoms Pb

Well, honey, in one mole of copper II sulfate, there are 4 moles of oxygen atoms. So, if you're asking about moles of oxygen molecules (O₂), then the answer is 8 moles. But if you're talking about individual oxygen atoms, then it's 4 moles. Either way, you've got a whole lotta oxygen hanging out with that copper II sulfate.

To determine the number of moles of water in 72.08g of H2O, we first need to calculate the molar mass of water (H2O). The molar mass of water is approximately 18.015 g/mol (2 hydrogen atoms with a molar mass of 1.008 g/mol each, and 1 oxygen atom with a molar mass of 16.00 g/mol).

Next, we use the formula: moles = mass / molar mass. Plugging in the values, we get moles = 72.08g / 18.015 g/mol ≈ 4 moles of water. Therefore, there are approximately 4 moles of water in 72.08g of H2O.

follow the avagardo number

here,

2.60x10^23 molecules of H2O X 1mole

-------

6.02x10^23 molecule of H2O ( molecule of H2O cancel and just remain with mole )

so,

2.60x10^23

----------------- moles

6.02x10^23

your final product wii be 0.43 mole of H20

source

me rata mokai

The a.m.u. is defined as the fraction of 1/12 of an atom of the carbon-12 isotope. The value is pretty nearer to the mass of a hydrogen atom. Therefore, in every compound, the gram molecular weight is numerically equal to the molecular mass in atomic mass units. Therefore the gram molecular weight of NaOH is 40 g/mol.

When an electron moves from a lower to a higher energy level, it absorbs energy and jumps to a higher orbit. This process is known as excitation. The electron can then release this absorbed energy as light when it moves back down to a lower energy level.

The molar mass of silver is approximately 107.87 g/mol. Therefore, the mass of 2.6 moles of silver would be 2.6 moles x 107.87 g/mol = 280.3 grams.

you take the mass of Al plus three Br. (27.0) + 3(80.0)

the answer is 267.

Basically, because "Why not?"

Something needs to be the standard. Carbon-12 is fairly common, and it's not oxygen (which was the previous standard; unfortunately, some people took naturally occurring oxygen as the standard and others took oxygen-16 specifically.).

Indeed, the standard was changed from oxygen to be a compromise between the chemists and physicists who used the differing definitions for Oxygen.

It is not Hydrogen because it was not easy to use experimentally to compare elements. (See here http://www.enotes.com/earth-science/atomic-mass-weight)

A detailed history is given here (http://www.iupac.org/publications/ci/2004/2601/1_holden.html).

To find the molecular mass if specific volume is given, you can use the ideal gas law. The ideal gas law relates the pressure, volume, temperature, and the number of moles of gas to the gas constant. By rearranging the ideal gas law equation and solving for the molecular mass, you can determine the molecular mass of the gas.

The molar mass of MgSO4.7H2O (magnesium sulfate heptahydrate) is calculated as the sum of the individual atomic masses of magnesium (Mg), sulfur (S), oxygen (O), and hydrogen (H). The molecular mass is approximately 246.47 g/mol.

2.80 moles of Na represents 2.80 times Avogadro's number of sodium atoms, which is approximately 1.69 x 10^24 atoms of sodium.

The term molecular mass is used for water because it exists as discrete molecules containing two hydrogen atoms and one oxygen atom. Aluminum chloride, on the other hand, does not exist as discrete molecules but as an ionic compound made up of aluminum and chlorine atoms held together by ionic bonds. Therefore, the term formula mass is used to describe the total mass of one formula unit of aluminum chloride.

The molecular mass of hydrogen sulfide (H2S) is 34.08 grams per mole.

The molecular mass of adrenaline, also known as epinephrine, is approximately 183.21 g/mol.