Determine the answer for the equation below with correct number of significant figures: 3.215 x 13.2 ÷ 0.218 = _______

How are the molecular mass and molar mass of a compound similar and how are they different?

4vir4ik [10]

Answer:

Similarities: both state the mass of chemical species and they have the same numerical value

Differences: molecular mass refers to one single molecule and molar mass refers to one mole of a molecule

Explanation:

The molecular mass is the value of the mass of each molecule and it is measured in mass units (u). It is calculated adding the mass of each atom of the molecule.

The molar mass is the value of the mass of one mole of molecules, which means the mass of 6.022140857 × 10²³ molecules. The unit is g/mol.

For example, we can consider the methane molecule, which has the chemical formula of CH₄:

Molecular mass CH₄ = C mass + 4 x (H mass)

Molecular mass CH₄ = 12.01 + 4 x (1.01)

Molecular mass CH₄ = 16.05 u

Now to calculate the molar mass we multiply the value of the molecular mass by the Avogadro number and convert the units to g/mol:

Molar mass CH₄: 16.05 x $\frac{1}{6.022140857 x 10x^{23} } g$ x 6.022140857 × 10²³ mol⁻¹

Molecular mass CH₄ = 16.05 g / mol

5 0

3 years ago

How many molecules are in a mole of H2O

belka [17]

1023 molecules or atoms depending on substance

7 0

2 years ago

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What are the 3 most important ecosystem services of a coral reef

kkurt [141]

2 Corsls provide treatments

3 0

3 years ago

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Perform the calculation and record the answer with the correct number of significant figures.

kotykmax [81]

The question is incomplete, here is the complete question:

A. (6.5-6.10)/3.19

B. (34.123 + 9.60) / (98.7654 - 9.249)

Answer:

For A: The answer becomes 0.1

For B: The answer becomes 0.4884

Explanation:

Significant figures are defined as the figures present in a number that expresses the magnitude of a quantity to a specific degree of accuracy.

Rules for the identification of significant figures:

Digits from 1 to 9 are always significant and have infinite number of significant figures.
All non-zero numbers are always significant. For example: 664, 6.64 and 66.4 all have three significant figures.
All zeros between the integers are always significant. For example: 5018, 5.018 and 50.18 all have four significant figures.
All zeros preceding the first integers are never significant. For example: 0.00058 has two significant figures.
All zeros after the decimal point are always significant. For example: 2.500, 25.00 and 250.0 all have four significant figures.
All zeroes used solely for spacing the decimal point are not significant. For example: 10000 has one significant figure.

Rule applied for addition and subtraction:

The least precise number present after the decimal point determines the number of significant figures in the answer.

Rule applied for multiplication and division:

In case of multiplication and division, the number of significant digits is taken from the value which has least precise significant digits

For A: (6.5-6.10)/3.19

This a a problem of subtraction and division.

First, the subtraction is carried out.

$\Rightarow \frac{6.5-6.10}{3.19}=\frac{0.4}{3.19}$

Here, the least precise number after decimal was 1.

$\Rightarrow \frac{0.4}{3.19}=0.125$

Here, the least precise number of significant digit is 1. So, the answer becomes 0.1

For B: (34.123 + 9.60) / (98.7654 - 9.249)

This a a problem of subtraction, addition and division.

First, the subtraction and addition is carried out.

$\Rightarow \frac{34.123+9.60}{98.7654-9.249}=\frac{43.723}{89.5164}=\frac{43.72}{89.516}$

Here, the least precise number after decimal in addition are 2 and in subtraction are 3

$\Rightarrow \frac{43.72}{89.516}=0.48840$

Here, the least precise number of significant digit are 4. So, the answer becomes 0.4884

6 0

3 years ago

Which of the following scientists made an important contribution to quantum mechanics: (i) Bohr (ii) deBroglie (iii) Heisenberg

grandymaker [24]

Answer:

(i) Bohr; (ii) de Broglie; (iii) Heisenberg (v) Schrödinger

Explanation:

(i) Niels Bohr — 1913 — proposed that electrons travel in fixed orbits with quantized energy levels and that they jump from one energy level to another by absorbing or emitting quanta of light.

(ii) Louis de Broglie — 1924 — proposed the wave nature of electrons and suggested that all matter behaves as both waves and particles (wave-particle duality).

(iii) Werner Heisenberg — 1927 — formulated quantum mechanics in terms of matrices and proposed his famous uncertainty principle.

(v) Erwin Schrödinger — 1926 — applied wave mechanics to the electron in a hydrogen atom, showing that electrons exist in orbitals rather that orbits.

(iv) Ernest Rutherford — 1911 — proposed that atoms have most of their mass in a central nucleus (nuclear atom). Quantum mechanics had not yet been invented.

4 0

3 years ago

Determine the answer for the equation below with correct number of significant figures: 3.215 x 13.2 ÷ 0.218 = ________