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Questions and Answers
Why do colloidal suspensions not coagulate spontaneously?
Why do colloidal suspensions not coagulate spontaneously?
- Colloidal particles have a low surface-to-mass ratio, which promotes coagulation.
- Colloidal particles are large and have a small surface-to-mass ratio, which prevents coagulation.
- Colloidal particles are both positively or negatively charged, and thus repel one another. (correct)
- Colloidal particles have a high density, preventing them from coagulating.
What is the purpose of gravimetric calculations?
What is the purpose of gravimetric calculations?
- To determine the weight of solute from the weight of solvent.
- To determine the weight of analyte from the weight of precipitate. (correct)
- To determine the weight of solvent from the weight of precipitate.
- To determine the weight of precipitate from the weight of analyte.
What causes the colloidal particles to have a negative charge?
What causes the colloidal particles to have a negative charge?
- Agglomeration of chloride ions (Cl-1).
- Adsorption of silver ions (Ag+1).
- Adsorption of excess chloride ions (Cl-1). (correct)
- Adsorption of silver nitrate (AgNO3).
What prevents colloidal particles from settling out of solution under the influence of gravity?
What prevents colloidal particles from settling out of solution under the influence of gravity?
What is the SI unit for the amount of a chemical substance?
What is the SI unit for the amount of a chemical substance?
What does an empirical formula give?
What does an empirical formula give?
What is the mass of the residue ignited at a high temperature to give 0.5394 g of pure Fe2O3?
What is the mass of the residue ignited at a high temperature to give 0.5394 g of pure Fe2O3?
What does stoichiometry involve?
What does stoichiometry involve?
Which element is chosen as a standard to establish an atomic weight scale?
Which element is chosen as a standard to establish an atomic weight scale?
What kind of substances are neutral species according to the text?
What kind of substances are neutral species according to the text?
What does the molecular formula specify?
What does the molecular formula specify?
What is the percent composition of Mg in Mg(NO3)2?
What is the percent composition of Mg in Mg(NO3)2?
How many moles of carbon atoms are there in 0.0022 grams of CO2?
How many moles of carbon atoms are there in 0.0022 grams of CO2?
What is the empirical formula of a compound that contains 60% oxygen and 40% sulfur by mass?
What is the empirical formula of a compound that contains 60% oxygen and 40% sulfur by mass?
If a compound contains 72% manganese and the remainder is oxygen, what is its empirical formula?
If a compound contains 72% manganese and the remainder is oxygen, what is its empirical formula?
What is the atomic weight of iron (Fe) if 0.5 gram of iron contains a certain number of moles?
What is the atomic weight of iron (Fe) if 0.5 gram of iron contains a certain number of moles?
In the chemical reaction 2NaI + Pb(NO3)2 -> 2NaNO3 + PbI2, how many moles of aqueous sodium nitrate are produced if 1 mole of Pb(NO3)2 reacts?
In the chemical reaction 2NaI + Pb(NO3)2 -> 2NaNO3 + PbI2, how many moles of aqueous sodium nitrate are produced if 1 mole of Pb(NO3)2 reacts?
In a chemical reaction, if the known mass of a substance in grams is transformed to a corresponding number of moles, what should be the next step in the stoichiometric calculation?
In a chemical reaction, if the known mass of a substance in grams is transformed to a corresponding number of moles, what should be the next step in the stoichiometric calculation?
Colloidal particles can be retained by ordinary filters.
Colloidal particles can be retained by ordinary filters.
Coagulation occurs when a liquid starts to thicken and become solid.
Coagulation occurs when a liquid starts to thicken and become solid.
Colloidal suspensions are stable and do not coagulate spontaneously because the colloidal particles are positively or negatively charged, and thus attract one another.
Colloidal suspensions are stable and do not coagulate spontaneously because the colloidal particles are positively or negatively charged, and thus attract one another.
The aim of gravimetric calculations is to find the weight of the precipitate from the weight of analyte.
The aim of gravimetric calculations is to find the weight of the precipitate from the weight of analyte.
The number of moles of carbon in 0.0022 grams of CO2 is 5x10^-5
The number of moles of carbon in 0.0022 grams of CO2 is 5x10^-5
The empirical formula merely shows the relative numbers of atoms of each element in the composition.
The empirical formula merely shows the relative numbers of atoms of each element in the composition.
Oxygen makes up 60% of the mass in a compound with sulfur, and the empirical formula is SO3.
Oxygen makes up 60% of the mass in a compound with sulfur, and the empirical formula is SO3.
Stoichiometric calculations involve converting the known mass of a substance in grams to a corresponding number of moles, followed by adjusting for stoichiometry and then converting the number of moles back to the required metric units.
Stoichiometric calculations involve converting the known mass of a substance in grams to a corresponding number of moles, followed by adjusting for stoichiometry and then converting the number of moles back to the required metric units.
In the chemical reaction 2NaI + Pb(NO3)2 -> 2NaNO3 + PbI2, 1 mole of Pb(NO3)2 reacts to produce 1 mole of solid lead iodide.
In the chemical reaction 2NaI + Pb(NO3)2 -> 2NaNO3 + PbI2, 1 mole of Pb(NO3)2 reacts to produce 1 mole of solid lead iodide.
If a compound contains 72% manganese and the remainder is oxygen, its empirical formula is MnO2.
If a compound contains 72% manganese and the remainder is oxygen, its empirical formula is MnO2.
The molar mass of CaO is 56.077 g/mol.
The molar mass of CaO is 56.077 g/mol.
The molar mass of water is 18.015 g/mol.
The molar mass of water is 18.015 g/mol.
The atomic weight of magnesium is 24.31 amu.
The atomic weight of magnesium is 24.31 amu.
In the chemical reaction 2NaI + Pb(NO3)2 -> 2NaNO3 + PbI2, if 1 mole of Pb(NO3)2 reacts, 2 moles of aqueous sodium nitrate are produced.
In the chemical reaction 2NaI + Pb(NO3)2 -> 2NaNO3 + PbI2, if 1 mole of Pb(NO3)2 reacts, 2 moles of aqueous sodium nitrate are produced.
An empirical formula specifies the number of atoms in a molecule.
An empirical formula specifies the number of atoms in a molecule.
The atomic weight of iron (Fe) is 55.847 amu.
The atomic weight of iron (Fe) is 55.847 amu.
The mole contains 6.02×10^23 items.
The mole contains 6.02×10^23 items.
To establish an atomic weight scale, one element is chosen as a standard and given a numerical value.
To establish an atomic weight scale, one element is chosen as a standard and given a numerical value.
Stoichiometry involves predicting the quantities of product materials required to produce a given quantity of reactants.
Stoichiometry involves predicting the quantities of product materials required to produce a given quantity of reactants.
The formula weight of MgCl2 is 95.21 amu.
The formula weight of MgCl2 is 95.21 amu.
Each formula unit of Mg(NO3)2 contains one Mg atom, two N atoms, and six O atoms.
Each formula unit of Mg(NO3)2 contains one Mg atom, two N atoms, and six O atoms.
The percent composition of Mg in Mg(NO3)2 is 16.39%.
The percent composition of Mg in Mg(NO3)2 is 16.39%.
