Answer:
B. Measures of central tendency
Explanation:
Mean, median and mode are best described as measures of central tendency of a given data set.
Mean is the average of the samples given
Mode is the data point with the most frequent occurrence
Median is the data point that lies in the middle
- All these parameters tells us how far a data point is from the middle or how close they are.
Answer:
HF is the limiting reactant
Explanation:
The balanced equation for the reaction is given below:
SiO₂ + 4HF —> SiF₄ + 2H₂O
From the balanced equation above,
1 mole of SiO₂ reacted with 4 moles of HF.
Finally, we shall determine the limiting reactant. This can be obtained as illustrated below:
From the balanced equation above,
1 mole of SiO₂ reacted with 4 moles of HF.
Therefore, 7.5 moles of SiO₂ will react with = 7.5 × 4 = 30 moles of HF.
From the calculation made above, we can see clearly that it will take a higher amount (i.e 30 moles) of HF than what was given from the question (i.e 5 moles) to react completely with 7.5 moles of SiO₂.
Therefore, HF is the limiting reactant and SiO₂ is the excess reactant.
Answer:
Explanation:
Electrovalent is a word often associated with chemical bonding in the field of chemistry. It is special type of bond that occurs between metals and non-metals.
These bond types are interatomic interactions occurring between two atoms to ensure that they attain stable configurations.
- This bond type is also known as ionic bonds.
- It occurs between two species with a large electronegative diffference i.e one specie is electropositive and the other highly electronegative.
- The more electropositive specie is metal and it readily loses its valence electrons.
- The electronegative non-metal gains the electrons and becomes negatively charged.
- The electrostatic attraction between the metal and non-metals yields the electrovalent bonds.
The chemical equation represents the reaction describes is;
4NH3 + 5O2 = 4NO + 6H2O
Therefore 4 moles of NH3 reacts with 5 moles of O2.
1 mole of O2 (molar mass) = 2 * 16 = 32g.
5 moles of O2 = 5 * 32 = 160g
4 moles of NH3 = 4 (14 + 3*1) = 68g
Therefore, 68g of NH3 reacts with 160g of O2.
But, we have only 4.5 g of oxygen.
68g reacts with 160g
Xg reacts with 4.5
X = 68*4.5 / 160 = 1.9125g
