Here we have to choose the right option which tells the moles of CaCl₂ will react with 6.2 moles of AgNO₃ in the reaction
2AgNO₃ + CaCl₂→ 2AgCl + Ca(NO₃)₂
6.2 moles of silver nitrate (AgNO₃) will react with B. 3.1 moles of calcium chloride (CaCl₂).
From the reaction: 2AgNO₃ + CaCl₂→ 2AgCl + Ca(NO₃)₂
Thus 2 moles of AgNO₃ reacts with 1 mole of CaCl₂
Henceforth, 6.2 moles of AgNO₃ reacts with 
= 3.1 moles of CaCl₂.
1 mole of CaCl₂ reacts with 2 moles of AgNO₃. Thus-
A. 2.2 moles of CaCl₂ will react with 2.2×2 = 4.4 moles of AgNO₃.
C. 6.2 moles of CaCl₂ will reacts with 6.2×2 = 12.4 moles of AgNO₃.
D. 12.4 moles of CaCl₂ will reacts with 12.4 × 2 = 24.8 moles of AgNO₃
Thus the right answer is 6.2 moles of AgNO₃ will react with 3.1 moles of CaCl₂.
Explanation:
from the graph study about oxygen content of Earth's atmosphere, we can understand that
1)
4 billions year ago = None, 3 billions year ago = Cyanobacteria and Archaea , 2 and 1 billions year ago = Bacteria and Green algae , 500 Ma = invertebrate fossils started to existence. Early land plants came in to existence around 398 MA that is Devonian. Dinosaurs are came in to existence during Triassic and Jurassic that is around 251 Ma. Man and animals are recent organism came under Holocene that is 11000 years ago.
2)
The first cells on the earth are anaerobic microorganisms, as the CO2 level is too high they survive by using CO2.
3)
Starting around 2.7 billion years ago, photosynthesis by Cyanobacteria and later plants , pumped “OXYGEN” in to the atmosphere. This caused the decline of anaerobic bacteria and allows the diversification of animals as seen in “CAMBRIAN” around 500 millions year ago.
Early vascular plants “CAPTURED” CO2 starting before the Carboniferous period that began around 350 millions year.Leading to lower temperatures and allowing and allowing the seed plants to outcompetes seedless plants.
Modern human activities has raised both “CO2 and METHANE” level in the atmosphere to over leading to higher temperature and extinction of other species.
Answer:
a. 0.119mol Kr
Explanation:
To solve this problem, we must understand that;
Mass = number of moles x molar mass
Molar mass of Kr = 83.3g/mol
Ar = 40g/mol
He = 4g/mol
Ne = 20.18g/mol
a0.119 mol Kr mass = 0.119 x 83.3 = 9.9g
b 0.400 mol Ar mass = 0.4 x 40 = 16g
C 1.25 mol He mass = 1.25 x 4 = 5g
d 2.02 mol Ne mass = 2.02 x 20.18 = 40.8
Krypton is the answer
Explanation:
a) when zinc burnt in oxygen.
2Zn + O2 -----∆-----> 2ZnO(black residue)
b) when carbon burnt in oxygen.
C+O2----∆---> CO2.
c) when sulphur burnt in oxygen.
S+O2-----∆-----> SO2.
d) when Calcium burnt in oxygen.
2Ca+O2-----∆-----> 2CaO(black residue)
e) when Magnesium burnt in oxygen.
2Mg+O2-----∆----> 2MgO.
f) when sodium burnt in oxygen.
4Na+O2----∆-----> 2Na2O.
hope all these reactions help you.
