Answer:-A. It is less than 890 kJ/mol because the amount of energy required to break bonds is less than the amount of energy released in forming bonds.
Explanation: Endothermic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat and 
for the reaction comes out to be positive.
Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and for the reaction comes out to be negative.
In the formation of new bonds more energy is released than is required to break the existing bonds, heat is released.
In the formation of bonds less energy is released than is required to break the existing bonds, heat is absorbed.
Answer:
Explanation:
Each value on the scale represents 10 times the previous value.
Subtract 1 from 6, so 10 to the power of 5 is the difference.
The mass of calcium hydroxide that is formed when 10.0 g of CaO reacts with 10.0 g of water is 13.024 grams
calculation
from the equation
CaO + H2O → Ca(OH)2,
1 moles of CaO reacted with 1 moles of H2O to form 1 moles of Ca(OH)2
find the moles of each reactant
moles=mass/molar mass
moles of CaO= 10 g/56 g/mol=0.179 moles
moles of H2O = 10 g/18 g/mol 0.556 moles
CaO is the limiting reagent therefore by use of mole ratio of CaO:Ca(OH)2 which is 1:1 moles of Ca(OH)2 is = 0.179 moles
mass= moles x molar mass
= 0.176 moles x 74 g/mol = 13.024 grams
Answer:
134.8 mmHg is the vapor pressure for solution
Explanation:
We must apply the colligative property of lowering vapor pressure, which formula is: P° - P' = P° . Xm
P° → Vapor pressure of pure solvent
P' → Vapor pressure of solution
Xm → Mole fraction for solute
Let's determine the moles of solute and solvent
17.5 g . 1 mol/180 g = 0.0972 moles
82 g . 1mol / 32 g = 2.56 moles
Total moles → moles of solute + moles of solvent → 2.56 + 0.0972 = 2.6572 moles
Xm → moles of solute / total moles = 0.0972 / 2.6572 = 0.0365
We replace the data in the formula
140 mmHg - P' = 140 mmHg . 0.0365
P' = - (140 mmHg . 0.0365 - 140mmHg)
P' = 134.8 mmHg
From the fact that oxygen is in group 16 and carbon is in group 14, the structure of CO2 must be O=C=O. In methane, there is no bond between any of the hydrogen atoms. The structure of H2O2 is H–O–O–H.
Carbon is in group 14 hence it has four valence electrons and oxygen is in group 16 hence it has six valence electrons. This implies that each oxygen atom will share four electrons with carbon in a covalent bond to form the structure O=C=O.
In CH4, we know that carbon is tetravalent so it forms for bonds. Therefore, there is no bond between hydrogen atoms so it bonds with each hydrogen atom; hydrogen only forms one bond.
In H2O2, there is the peroxide ion that has the structure O-O. Hence, the correct structure of H2O2 is H–O–O–H.
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