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>
4 Hydrogen Atoms should be correct. Because the 4 infront of it signifies the amount of hydrogen. It would also be 4 hydrogen atoms if it were written as H4N3, because the 4 is still around the H (as long as the 4 is under scored)
<u>Answer:</u> The mass of phosphorus that is present for given amount of calcium is 28.53 g.
<u>Explanation:</u>
We are given:
Mass of calcium = 50 grams
The chemical formula of calcium phosphate is 
Molar mass of calcium = 40 g/mol
Molar mass of phosphorus = 31 g/mol
In 1 mole of calcium phosphate, 120 grams of calcium is combining with 62 grams of phosphorus.
So, 50 grams of calcium will combine with = 
of phosphorus.
Hence, the mass of phosphorus that is present for given amount of calcium is 28.53 g.
Answer:
Explanation:
There are 3 types of plastids :-
1) Chloroplasts:- The green plastids which contain chlorophyll pigments for photosynthesis.
2) Chromoplasts:-The coloured plastids for pigment synthesis and storage.
3) Leucoplasts:- The colourless plastids for monoterpene synthesis found in non- photosynthetic parts of the plants.
They are of three types:-
a) Amyloplasts- stores starch.
b) Proteinoplasts- stores proteins.
c) Elaioplasts- stores fats and oils.
