Answer:
0.4 M
Explanation:
Molarity is defined as moles of solute, which in your case is sodium hydroxide,
NaOH
, divided by liters of solution.
molarity
=
moles of solute
liters of solution
Notice that the problem provides you with the volume of the solution, but that the volume is expressed in milliliters,
mL
.
Moreover, you don't have the number of moles of sodium hydroxide, you just have the mass in grams. So, your strategy here will be to
determine how many moles of sodium hydroxide you have in that many grams
convert the volume of the solution from milliliters to liters
So, to get the number of moles of solute, use sodium hydroxide's molar mass, which tells you what the mass of one mole of sodium hydroxide is.
7
g
⋅
1 mole NaOH
40.0
g
=
0.175 moles NaOH
The volume of the solution in liters will be
500
mL
⋅
1 L
1000
mL
=
0.5 L
Therefore, the molarity of the solution will be
c
=
n
V
c
=
0.175 moles
0.5 L
=
0.35 M
Rounded to one sig fig, the answer will be
c
=
0.4 M
Explanation:
D. melting ice on roads and sidewalks, i think
<span>The correct option is C. The concentration of phosphate inside the cytosol is already greater than the concentration of phosphate in the surrounding fluid, yet, the cell still want to move more phosphate into the cell. To do this, energy is needed to move the phosphate ions against the concentration gradient, so the type of transportation requires is ACTIVE TRANSPORT.</span><span />
Sound travels in waves and the height of the wave is the loudness of the sound.
To decrease sound, you need to make the waves not so high, so you can
- decrease the amplitude
- decrease the height of the crest (lower the top of the wave down)
- increase the height of the trough (bring the bottom of the wave up)
It's all about getting the wave to be closer to the center, to not be so high and low, but to be flatter.
(picture taken from sound . eduation website)
