A molecule with two strong bond dipoles can have no molecular dipole if the bond dipoles cancel each other out by pointing in exactly opposite directions. For example, in carbon dioxide (a linear molecule), the carbon-oxygen bonds have a <span>large dipole moment. However, because one dipole points to the left and the other to the right the dipole is cancelled.</span>
Answer:
Henry Moseley
Explanation:
Dmitry Mendeleef and Lothar Meyer proposed a periodic table based on the atomic mass.
They stated a periodic law expressed as "chemical properties of elements are a periodic function of their atomic weights".
But, Henry Moseley in 1900s re-stated periodic law by changing the basis of the law from atomic weight to atomic number.
The present periodic law is stated as "the properties of elements are a periodic function of their atomic number".
Answer:
46.40 g.
Explanation:
- It is a stichiometric problem.
- The balanced equation of the reaction: 4K + O₂ → 2K₂O.
- It is clear that 4.0 moles of K reacts with 1.0 mole of oxygen produces 2.0 moles of K₂O.
- We should convert the mass of K (38.5 g) into moles using the relation:
<em>n = mass / molar mass,</em>
n = (38.5 g) / (39.098 g/mol) = 0.985 mole.
<em>Using cross multiplication:</em>
4.0 moles of K produces → 2.0 moles of K₂O, from the stichiometry.
0.985 mole of K produces → ??? moles of K₂O.
∴ The number of moles of K₂O produced = (0.985 mole) (2.0 mole) / (4.0 mole) = 0.4925 mole ≅ 0.5 mole.
- Now, we can get the mass of K₂O:
∴ mass = n x molar mass = (0.5 mole) (94.2 g/mol) = 46.40 g.
Answer:
Synthesis - 4
reversible- 2
exchange- 1
decomposition-3
Explanation:
In synthesis reaction two or more components combines to form a single product. example 2H2+O2⇒2H2O
In reversible reaction two reactants combine to form two products . The products then reacts and forms back the reactants. example N2 +3H2 ⇒2NH3
In exchange reaction there is an alternation of ions of reactants to form new products. AB+CD ⇒AC + BD
In decomposition reaction, molecules of a compound break down by the action of heat or light or catalyst. example CaCO3 ⇒CaO +CO2
Answer:
The London dispersion force is the weakest intermolecular force. The London dispersion force is a temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make the atoms form temporary dipoles.
