Answer:
Light and sound both are waves, but sound requires a material medium to travel, and hence cannot travel in empty space while light can travel through vacuum but not through opaque materials. Both undergo refraction, diffraction and interference.
Explanation:
Answer:
Your strategy here will be to use the molar mass of potassium bromide,
KBr
, as a conversion factor to help you find the mass of three moles of this compound.
So, a compound's molar mass essentially tells you the mass of one mole of said compound. Now, let's assume that you only have a periodic table to work with here.
Potassium bromide is an ionic compound that is made up of potassium cations,
K
+
, and bromide anions,
Br
−
. Essentially, one formula unit of potassium bromide contains a potassium atom and a bromine atom.
Use the periodic table to find the molar masses of these two elements. You will find
For K:
M
M
=
39.0963 g mol
−
1
For Br:
M
M
=
79.904 g mol
−
1
To get the molar mass of one formula unit of potassium bromide, add the molar masses of the two elements
M
M KBr
=
39.0963 g mol
−
1
+
79.904 g mol
−
1
≈
119 g mol
−
So, if one mole of potassium bromide has a mas of
119 g
m it follows that three moles will have a mass of
3
moles KBr
⋅
molar mass of KBr
119 g
1
mole KBr
=
357 g
You should round this off to one sig fig, since that is how many sig figs you have for the number of moles of potassium bromide, but I'll leave it rounded to two sig figs
mass of 3 moles of KBr
=
∣
∣
∣
∣
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
a
a
360 g
a
a
∣
∣
−−−−−−−−−
Explanation:
<em>a</em><em>n</em><em>s</em><em>w</em><em>e</em><em>r</em><em>:</em><em> </em><em>3</em><em>6</em><em>0</em><em> </em><em>g</em><em> </em>
Answer:
16.015668 M
Explanation:
Concentration is mols/L
nacl molar mass is 58.44277 g/mol
moles = mass/molar mass
moles = 4.00391699
4mol/0.250L = 16.015668 M solution
Answer:
Empirical formula of 81.8 carbon and 18.2 hydrogen
Steps
- Find the empirical formula of a compound that has 81.8% of Carbon (C), 18.2% of Hydrogen (H).
- Divide by fractional component of each mole value: C=1.5354936431103, H=4.0709872862205Round to closest whole numbers: C=2, H=4
<h3> Combine to get the empirical formula: C2H4</h3>