Answer:
Option (B) is correct
Explanation:
Buffers are of three kinds - (1) mixture of weak acid and it's salt, (2) mixture of weak base and it's salt and (3) mixture of weak acid and weak base
if we add sodium acetate into a solution of acetic acid then the mixture would act as a buffer due to presence of weak acid (acetic acid) and it's salt (sodium acetate).
If we add some amount of sodium hydroxide into a solution of acetic acid then some amount of acetic acid gets converted to it's sodium salt. Hence, unreacted amount of acetic acid and it's salt acts as a buffer.
So, either sodium acetate or sodium hydroxide addition would produce a buffer.
Answer:
The answer is
<h2>6.68 g/cm³</h2>
Explanation:
The density of a substance can be found by using the formula
From the question
mass of mineral = 14.7 g
volume = 2.2 cm³
It's density is
We have the final answer as
<h3>6.68 g/cm³</h3>
Hope this helps you
To determine the density, we use the following formula:
mass= 2.813 grams
volume= ?
we need to first calculate the volume before we can solve for the density. since the question states that the sample has a spherical shape, we can use the volume formula of spheres to find it.
radius (r)=
=
let's plug in the values
V=
we need to change the
to
using the following conversion
1 cm= 10 mm
now we can find the density.
density= 2.813 grams/ 0.268 cm=
10.5 g/cm3
Answer: Wheel and Axle
Both of these work together to form a simple machine. You can't have one without the other.
If you try to turn just the axle itself, then you'll find it takes a lot of work. This is because the inertia of the axle wants to keep the object at rest. Also, you won't have a lot of torque due to the small radius compared to what a doorknob can offer.
Using a doorknob is like putting a (steering) wheel on an axle. This increases the radius and therefore increases the torque. You put in less work into the system and get more out of it.
Answer:
Water is a human necessity. Therefore, it is one of the first things a human settlement would need to have. A community cannot thrive without a water source.