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>
I believe the answer is C) there is an obvious reasoning for this all you have to do is eliminate answers that don't seem right for example, A)the plates are all moving the same direction every plate moves in different directions. B) The plates are all the same size. Well, it's really obvious that that is not true because every plate has its different shape and size. D) where two plates meet, they always move apart. If this were true, then we would never have earthquakes when plates meet earthquakes happen. so there for the answer is C)
Answer:
1140 mmHg
Explanation:
1 atmosphere is 760 mmHg, so 1.5 atmospheres is ...
1.5×760 mmHg = 1140 mmHg
Answer:
- <u><em>Magnesium and fluorine.</em></u>
Explanation:
<em>Ionic compounds</em> are formed by the electrostatic attraction of cations and anions.
Cations, positive ions, are formed when atoms lose electrons, and anions, negative ions, are formed when atoms gain electrons.
When two different atoms have similar atraction for electrons (electronegativity) they will not donate to nor catch electrons from each other, so cations and anions will not be formed. Instead, the atoms would prefer to share electrons forming covalent bonds to complete their outermost shell (octet rule).
Then, in order to form ionic compounds the electronegativities have to substantially different. This situation does not happen between two nonmetal elements, which nitrogen and sulfur are. Then, you can predict safely that nitrogen and sulfur will not form an ionic compound.
Ionic compounds, then require the electronegativity difference that exist between some metals and nonmetals. Being magnesium an alkaline earth metal, its electronegativity is very low. On the other hand, fluorine the first element of the group 17, has the highest electronegativity of all the elements.Thus magnesium and fluorine will have enough electronegativity difference to justify the exchange of electrons, forming ions and, consequently, ionic compounds.
