23. The atomic mass is calculated by adding the number of protons and neutrons. However, you cannot guess the number of neutrons. Refer to the periodic table. The atomic mass/mass no of Sodium is 23.
<h3>
Answer:</h3>
= 3.384 × 10^23 atoms
<h3>
Explanation:</h3>
We are given 18.016 g of sulfur
We are required to determine the number of atoms of sulfur
We will use the following steps;
<h3>Step 1: Determine the number of moles of sulfur </h3>
Number of moles = Mass ÷ molar mass
Molar mass of sulfur = 32.065 g/mol
Therefore;
Number of moles = 18.016 g÷ 32.065 g/mol
= 0.562 moles
<h3>Step 2: Determine the number of atoms </h3>
Using the Avogadro's constant;
1 mole of an element = 6.022 × 10^23 atoms
Therefore;
For 0.562 moles;
= 0.562 moles × 6.022 × 10^23 atoms
= 3.384 × 10^23 atoms
Therefore; there are 3.384 × 10^23 atoms in 18.016 g of Sulfur.
The addition of 0.1M HCl and 0.1M NaOH both of equal amounts is considered to be a neutralization reaction. A neutralization reaction is basically a double replacement reaction participated by both an acid and a base. In this case, the NaOH is the base while the HCl is the acid. The reaction will yield the following products: Water (H20) and aqueous Sodium Chloride (NaCl). Neutralization reactions always yield a salt and water as the end products.
<span>The alkali metal atom forms a +1 ion, while the alkaline earth metal atom forms a +2 ion. hope this helps</span>
Answer:
E = 1.8 x 10⁵ J/mol
Explanation:
We are being asked the enery per mol for an emission line corresponding to 649 nm.
The energy of a photon is given by the porduct of Planck's contant times the frequency of the radiation,
E = hν
We also know that the frequency is given by
ν = c/λ
where c is the speed of light (3 x 10 ^8 m/s) and λ is 649 nm given in the problem. Therefore the energy per photon will be given by
E= hc/λ = 6.626 x 10⁻³⁴Js x 3 x 10 ^8 m/s/ 649 x 10 ⁻⁹ m
E = 3.1 x 10 ⁻¹⁹ J/ photon
(Note the wavelength has to be in nanometers (1nm= 10⁻⁹ m) and that the energy we get is the energy per a single photon. Thus we will need to multiply this result by Avogadro's number to answer this question.
E = 3.1 x 10 ⁻¹⁹ J/ photon x 6.022 x 10 ²³photon/mol
E = 1.8 x 10⁵ J/mol