Answer:
<h2>2.79 moles</h2>
Explanation:
To find the number of moles in a substance given it's number of entities we use the formula
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
We have the final answer as
<h3>2.79 moles</h3>
Hope this helps you
Answer:
A - thinking of various research topics
Answer:
These activities describe the use of technology in science.
1) looking at cells through a microscope.
2) viewing stars through a telescope.
5) developing a computer model for earthquakes.
Explanation:
The moment a scientific instrument/equipment is involved in any scientific activity, there is a use of technology is such scientific activity.
Machines and equipment like Computers, Telescopes, and Microscope are technological.
Check all that apply:
1) looking at cells through a microscope
2) viewing stars through a telescope
3) observing a plant with the unaided eye
4) creating a blank data table by hand in a notebook
5) developing a computer model for earthquakes
Answer:
Here's what I get
Explanation:
1. In dilute NaOH
(a) Molecular equation
AlCl₃(aq) + 3NaOH(aq) ⟶ Al(OH)₃(s) + 3NaCl(aq)
(b) Ionic equation
You write the molecular formulas for solids, and you write the soluble ionic substances as ions.
Al³⁺(aq) + 3Cl⁻(aq) + 3Na⁺(aq) + 3OH⁻(aq) ⟶ Al(OH)₃(s) + 3Na⁺(aq) + 3Cl⁻(aq)
(c) Net ionic equation
To get the net ionic equation, you cancel the ions that appear on each side of the ionic equation.
Al³⁺(aq) + <u>3Cl⁻(aq)</u> + <u>3Na⁺(aq</u>) + 3OH⁻(aq) ⟶ Al(OH)₃(s) + <u>3Na⁺(aq)</u> + <u>3Cl⁻(aq)
</u>
The net ionic equation is
Al³⁺(aq) + 3OH⁻(aq) ⟶ Al(OH)₃(s)
2. In excess NaOH
The aluminium hydroxide reacts with excess hydroxide to form sodium tetrahydroxoaluminate(III).
(a) Molecular equation
AlCl₃(aq) + 4NaOH(aq) ⟶ NaAl(OH)₄(aq) + 3NaCl(aq)
(b) Ionic equation
Al³⁺(aq) + 3Cl⁻(aq) + 4Na⁺(aq) + 4OH⁻(aq) ⟶ Na⁺Al(OH)₄⁻(aq) + 3Na⁺(aq) + 3Cl⁻(aq)
(c) Net ionic equation
Al³⁺(aq) + 4OH⁻(aq) ⟶ Al(OH)₄⁻(aq)
