Answer:
63.05% of MgCO3.3H2O by mass
Explanation:
<em>of MgCO3.3H2O in the mixture?</em>
The difference in masses after heating the mixture = Mass of water. With the mass of water we can find its moles and the moles and mass of MgCO3.3H2O to find the mass percent as follows:
<em>Mass water:</em>
3.883g - 2.927g = 0.956g water
<em>Moles water -18.01g/mol-</em>
0.956g water * (1mol/18.01g) = 0.05308 moles H2O.
<em>Moles MgCO3.3H2O:</em>
0.05308 moles H2O * (1mol MgCO3.3H2O / 3mol H2O) =
0.01769 moles MgCO3.3H2O
<em>Mass MgCO3.3H2O -Molar mass: 138.3597g/mol-</em>
0.01769 moles MgCO3.3H2O * (138.3597g/mol) = 2.448g MgCO3.3H2O
<em>Mass percent:</em>
2.448g MgCO3.3H2O / 3.883g Mixture * 100 =
<h3>63.05% of MgCO3.3H2O by mass</h3>
Answer:
The correct statements that you must check are:
- The oxygen atom has a greater attraction for electrons than the hydrogen atom does (second statement).
- The electrons of the covalent bond are not shared equally between the hydrogen and oxygen atoms (fourth statement).
Explanation:
Electronegativity is the relative ability of an atom to pull the electrons in a covalent bond.
Hydrogen has an electronegativity of 2.20 and oxygen has 3.44. That means that oxygen attracts the electrons more strongly than hydrogen does (second statement).
As consequence, the electrons in the covalent bond H - O of water are not shared equally (fourth statement): the electron density will be higher around the O atoms.
Of course, this discards the statement telling that hydrogen atom attracts electrons much more strongly than the oxygen atom, and the statement telling that hydrogen and oxigen have same electronegativity.
Such difference in electron densities creates a dipole moment, so you discard the last statement (that the water dipole moment is equal to zero).
Answer:
Latent heat of fusion of the substance is 
Explanation:
Latent heat of fusion denotes amount of energy (heat) per unit mass required to melt a solid material at constant temperature and pressure i.e. at it's melting point
Here amount of heat required = 
Mass of unknown substance being melted = 18.5 kg
So, latent heat of fusion of the substance = (required heat energy to melt)/(mass of the unknown substance) = 
So, latent heat of fusion of the substance is
According to VSEPR theory, molecular geometry can be predicted by starting with the electron pair geometry about the central atom and adding atoms to some or all of the electron pairs.
Explanation:
The minimum amount of energy required by a substance to begin a reaction is known as the activation energy.
Therefore, we can conclude that when you strike a match, you provide activation energy that enables the flame to appear.
Whereas a catalyst helps in increasing the rate of reaction but it does not start the reaction. On the other hand, when reactants combine together then we get products.
Thus, we can conclude that options (a), (b), (c), and (e) are not correct.
Hence, option (d) is the correct answer.
