You must remember that oxidation number of hydrogen in acids is always +1, oxidation number of oxygen in oxides & acids is always -2... metals has always oxidation number on plus!
group NO3 comes from HNO3...and oxidation number of whole acid group is always on minus and equal to the amount of hydrogen atoms in this acid... so oxidation number of NO3 = -1
we have 2 NO3 groups so 2*(-1) = -2 and that is the reason why oxidation number of Fe in this formula must be +2... because sum of all elements always gives 0!
Now we could count of oxidation number for nitrogen... we write HNO3 and start counting from right to left:
3*(-2) from oxygens + 1 from hydrogen = -5
so nitrogen must have +5 oxidation number... because sum all in formula must be 0.
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.
Answer:
400 mL
Explanation:
Given data:
Mass of barium = 2.17 g
Pressure = 748 mmHg (748/760 = 0.98 atm)
Temperature = 21 °C ( 273+ 21 = 294k)
Milliliters of H₂ evolved = ?
Solution:
chemical equation:
Ba + 2H₂O → Ba(OH)₂ + H₂
Number of moles of barium:
Number of moles = mass/ molar mass
Number of moles = 2.17 g / 137.327 g/mol
Number of moles = 0.016 mol
Now we will compare the moles of barium with H₂.
Ba : H₂
1 : 1
0.016 : 0.016
Milliliters of H₂:
PV = nRT
V = nRT/P
V = 0.016 mol × 0.0821 atm. mol⁻¹.k⁻¹.L×294 k/0.98 atm
V = 0.39 atm. L/0.98 atm
V = 0.4 L
L to mL
0.4 × 1000 = 400 mL
Answer:
Empirical formula is CH₄
Molecular formula = C₂H₈
Explanation:
Mass of carbon = 37.5 g
Mass of hydrogen = 12.5 g
Molecular weight = 32 g/mol
Molecular formula = ?
Empirical formula = ?
Solution:
Number of gram atoms of C = 37.5 g /12g/mol = 3.125
Number of gram atoms of H = 12.5 g / 1.008 g/mol= 12.4
Atomic ratio:
C : H
3.125/3.125 : 12.4 /3.125
1 : 4
C : H : = 1 : 4
Empirical formula is CH₄
Molecular formula:
Molecular formula = n (empirical formula)
n = molar mass of compound / empirical formula mass
n = 32 / 16
n = 2
Molecular formula = n (empirical formula)
Molecular formula = 2 ( CH₄)
Molecular formula = C₂H₈
Give me 25 minutes and I’ll have the answers :)
