Answer:
C
Explanation:
Since the solution have an observable color, that means that it absorbs light in the visible region hence it can be determined by colorimetry. Secondly, KMnO4 is a reducing agent which can be titrated against an oxidizing agent and it's concentration accurately determined.
Anthony’s because it explains way more
Answer:
- <em><u>Mendeleev produced the first orderly arrangement of known elements.</u></em>
- <em><u>Mendeleev used patterns to predict undiscovered elements.</u></em>
Explanation:
- <u>Mendeleev produced the first orderly arrangement of known elements and used patterns to predict the undiscovered elements.</u>
Those two statments are true.
For the time being there were some 62 known elements. Before Medeleev some schemes to order part of the elements were proposed, but Medeleev showed the relationship between the atomic mass and the properties of the elements (supports second choice). This arrangement is known as the periodic table.
More importantly, Mendeleev predicted correctly the existance and properties of unknown elements, which is his major contribution: he left blanket spaces which where gradually filled when new elements where discovered (this supports the fourth choice).
The first modern chemistry book was written by Antoine Lavoisier (this discards first option).
Mendeleev ordered the elements by increasing mass number (this discards third choice), which was corrected later by the scientist Henry Moseley, who ordered the elements by increasing atomic number (number of protons).
Isotopes were not known by Mendeleev times, so this discards the last option.
<h3>
Answer:</h3>
B. C7H16 + 11O2 → 7CO2 + 8H2O
<h3>
Explanation:</h3>
- In a balanced chemical equation, the number of atoms of each element is equal on both sides of the equation.
- In this case, the balanced chemical equation is;
C7H16 + 11O2 → 7CO2 + 8H2O
Because, it has 7 carbon atoms, 16 hydrogen atoms and 22 oxygen atoms on each side of the equation.
- When an equation is balanced it obeys the law of conservation of mass such that the mass of reactants will be equal to the mass of products.
