Answer:
0.5 × 10²³ atoms of iodine
Explanation:
Given data:
Mass of calcium iodide = 12.75 g
Number of atoms of iodine = ?
Solution:
First of all we will calculate the number of moles of calcium iodide.
Number of moles = mass/ molar mass
Number of moles = 12.75 g/ 293.9 g/mol
Number of moles = 0.04 mol
In one mole of calcium iodide there are two moles of iodine.
Thus in 0.04 moles:
0.04 mol × 2 = 0.08 moles of iodine
Now we will use the Avogadro number:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ atoms
0.08 moles of iodine × 6.022 × 10²³ atoms / 1 mol
0.5 × 10²³ atoms of iodine.
The correct answer is reaction 2 most likely occurred in their experiment.
So the given two reactions are as follows:
1) Au³⁺(aq) + Co(s) --> Au(s) + Co³⁺(aq)
2) 2Au³⁺(aq) + 3Co(s) --> 2Au(s) + 3Co³⁺(aq)
Mass of Co = 6.087 g
Molar mass of Co = 58.933 g/mol
Moles of Co = = 0.1032
Mass of Au = 13.572 g
Molar mass of Au = 196.967 g/mol
Moles of Au = = 0.069
Now based on reaction 1) the molar ratio between Co and Au is 1:1
So as per this reaction 0.1032 moles of Co would produce 0.1032 mole of Au
Again based on reaction 2) the molar ratio between Co and Au is 3:2
So as per this reaction 0.1032 moles of Co would produce mole of Au
or, As per the second reaction 0.1032 moles of Co would produce 0.0688 moles of Au
A species whose oxidation number increases in a reaction is oxidized (reducing reagents or reactant).
For example, balanced chemical
reaction: 2KClO₃ → 2KCl + 3O₂<span>.
</span><span>Oxygen in the
reactant state has oxidation number -2 (+1 + 5 + 3 · x = 0) and it is
oxidized to 0 (in molecule of oxygen) in the product state.</span>
Answer:
Analyzing data and drawing conclusions
Explanation:
The scientific method is a process or method of inquiry that follows a series of sequential steps which helps a scientist to understand the world around him, draw conclusions and predict results.
The steps in the scientific method include:
1. Observation: the scientist observes his environment keenly and carefully.
2. Asking a question to identify the problem.
3. Conducting research to get information about the problem.
4. Making a hypothesis or an educated guess of a possible outcome.
5.Conducting experiments to test the hypothesis.
6. Analyzing data and drawing conclusions: this involves drawing inferences about experimental results and determining if the collected data supports the original hypothesis and determining if the hypothesis is correct.
7. Communicate results: presenting the result and data through various media, such a laboratory report.