Podcast
Questions and Answers
Which statement best explains how a chemical formula represents a molecule or compound?
Which statement best explains how a chemical formula represents a molecule or compound?
- It indicates the types and numbers of atoms present. (correct)
- It shows the mass of each atom in the molecule.
- It illustrates the physical state of the substance at room temperature.
- It indicates the arrangement of atoms with a diagram.
What is the significance of the subscript number 2 in the chemical formula of diatomic gases such as $O_2$ or $H_2$?
What is the significance of the subscript number 2 in the chemical formula of diatomic gases such as $O_2$ or $H_2$?
- It indicates that the gas is in its second energy level.
- It denotes the charge of the gas molecule is 2+.
- It represents that the molecule contains two atoms of that element. (correct)
- It signifies that the molecule is twice as stable as a single atom.
In writing formulas for ionic compounds, what principle ensures the compound is electrically neutral?
In writing formulas for ionic compounds, what principle ensures the compound is electrically neutral?
- The subscripts must always be the smallest possible whole numbers.
- The positive and negative charges (valency) are balanced such that the total charge is zero. (correct)
- The sum of the atomic masses of all ions must equal zero.
- Each ion must have an equal number of protons and electrons.
What does it mean when a chemical formula cannot be simplified further, such as with $H_2O$?
What does it mean when a chemical formula cannot be simplified further, such as with $H_2O$?
Which information is conveyed by a structural formula that is not typically provided by a molecular formula?
Which information is conveyed by a structural formula that is not typically provided by a molecular formula?
When naming covalent compounds, prefixes like 'di-' and 'penta-' are used to indicate what?
When naming covalent compounds, prefixes like 'di-' and 'penta-' are used to indicate what?
What distinguishes an empirical formula from a molecular formula?
What distinguishes an empirical formula from a molecular formula?
Considering the formula $Al_2(SO_4)_3$, what does the subscript '3' outside the parenthesis indicate?
Considering the formula $Al_2(SO_4)_3$, what does the subscript '3' outside the parenthesis indicate?
How do you determine whether a compound is ionic or covalent based on its formula or name?
How do you determine whether a compound is ionic or covalent based on its formula or name?
What is the correct name for the compound $N_2O_5$, given the rules for naming covalent compounds?
What is the correct name for the compound $N_2O_5$, given the rules for naming covalent compounds?
If a compound has the empirical formula $CH_2$, which of the following molecular formulas is possible for the compound?
If a compound has the empirical formula $CH_2$, which of the following molecular formulas is possible for the compound?
Consider two different compounds, Compound A ($C_2H_4$) and Compound B ($C_3H_6$). What can be said about their empirical formulas?
Consider two different compounds, Compound A ($C_2H_4$) and Compound B ($C_3H_6$). What can be said about their empirical formulas?
Which of the following is the correct formula for copper(II) sulfate?
Which of the following is the correct formula for copper(II) sulfate?
What is the correct name for the compound $Fe(NO_3)_3$, considering that iron can have multiple oxidation states?
What is the correct name for the compound $Fe(NO_3)_3$, considering that iron can have multiple oxidation states?
Determining compound names based on their composition is critical in chemistry. What would be the correct chemical name for the compound with the formula $AsBr_3$?
Determining compound names based on their composition is critical in chemistry. What would be the correct chemical name for the compound with the formula $AsBr_3$?
Given the chemical formula $C_6H_{12}O_6$ for glucose, what would be its empirical formula?
Given the chemical formula $C_6H_{12}O_6$ for glucose, what would be its empirical formula?
What is the formula of ammonium phosphate, given that ammonium is $NH_4^+$ and phosphate is $PO_4^{3-}$?
What is the formula of ammonium phosphate, given that ammonium is $NH_4^+$ and phosphate is $PO_4^{3-}$?
What is the systematic name for $NaClO_2$, which contains the polyatomic ion $ClO_2^-$?
What is the systematic name for $NaClO_2$, which contains the polyatomic ion $ClO_2^-$?
What is the molecular formula that corresponds to the empirical formula $C_2H_5$ and a molar mass of approximately 58 g/mol?
What is the molecular formula that corresponds to the empirical formula $C_2H_5$ and a molar mass of approximately 58 g/mol?
A compound contains 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen by mass. What is its empirical formula?
A compound contains 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen by mass. What is its empirical formula?
If a newly synthesized compound is found to have the empirical formula $CH$ and its molecular weight determination reveals that its molecular weight is 78 g/mol, what is the molecular formula of the compound?
If a newly synthesized compound is found to have the empirical formula $CH$ and its molecular weight determination reveals that its molecular weight is 78 g/mol, what is the molecular formula of the compound?
What information is needed to determine the molecular formula of a compound if you already know its empirical formula?
What information is needed to determine the molecular formula of a compound if you already know its empirical formula?
Which of the following pairs of compound name and formula is INCORRECTLY matched?
Which of the following pairs of compound name and formula is INCORRECTLY matched?
Two organic compounds, ethene ($C_2H_4$) and propene ($C_3H_6$), share the same empirical formula, which results in resembling characteristics. Despite this similarity, which of the subsequent properties would NOT be similar?
Two organic compounds, ethene ($C_2H_4$) and propene ($C_3H_6$), share the same empirical formula, which results in resembling characteristics. Despite this similarity, which of the subsequent properties would NOT be similar?
In a laboratory experiment, a compound is found to contain 24 g of carbon and 8 g of hydrogen. Determine the empirical formula of this compound.
In a laboratory experiment, a compound is found to contain 24 g of carbon and 8 g of hydrogen. Determine the empirical formula of this compound.
A gaseous compound is composed of 85.7% carbon and 14.3% hydrogen by mass. If its density at standard temperature and pressure (STP) is 2.5 g/L, what is its molecular formula?
A gaseous compound is composed of 85.7% carbon and 14.3% hydrogen by mass. If its density at standard temperature and pressure (STP) is 2.5 g/L, what is its molecular formula?
Given that the percent composition of a compound is 30.4% nitrogen and 69.6% oxygen, which formula represents the empirical formula of this compound?
Given that the percent composition of a compound is 30.4% nitrogen and 69.6% oxygen, which formula represents the empirical formula of this compound?
A compound is known to contain only carbon, hydrogen, and oxygen. If it consists of 40.00% carbon and 6.72% hydrogen by mass, what would be its empirical formula?
A compound is known to contain only carbon, hydrogen, and oxygen. If it consists of 40.00% carbon and 6.72% hydrogen by mass, what would be its empirical formula?
To properly determine the empirical formula of a new organic compound, a chemist performs combustion analysis. If 1.60 grams of the compound yields 3.52 grams of $CO_2$ and 1.44 grams of $H_2O$, what is the empirical formula?
To properly determine the empirical formula of a new organic compound, a chemist performs combustion analysis. If 1.60 grams of the compound yields 3.52 grams of $CO_2$ and 1.44 grams of $H_2O$, what is the empirical formula?
A hydrate of magnesium sulfate ($MgSO_4 \cdot xH_2O$) is heated until all the water is removed. If 4.92 grams of the hydrate yields 2.40 grams of anhydrous $MgSO_4$, what is the value of x?
A hydrate of magnesium sulfate ($MgSO_4 \cdot xH_2O$) is heated until all the water is removed. If 4.92 grams of the hydrate yields 2.40 grams of anhydrous $MgSO_4$, what is the value of x?
For the covalent compound disulfur dichloride, what is its chemical formula?
For the covalent compound disulfur dichloride, what is its chemical formula?
Determine the empirical formula of a compound that yields the following data from combustion analysis: 0.200 g of the compound produces 0.486 g of $CO_2$ and 0.199 g of $H_2O$ as the only products.
Determine the empirical formula of a compound that yields the following data from combustion analysis: 0.200 g of the compound produces 0.486 g of $CO_2$ and 0.199 g of $H_2O$ as the only products.
A certain compound is found to have a percent composition of 54.56% C, 9.15% H, and 36.29% O by mass. Given that its molar mass is approximately 88.0 g/mol, what is the correct molecular formula?
A certain compound is found to have a percent composition of 54.56% C, 9.15% H, and 36.29% O by mass. Given that its molar mass is approximately 88.0 g/mol, what is the correct molecular formula?
Consider the compound $X_2Y_3$ where X is a cation with a +3 charge. What is the charge of the anion Y?
Consider the compound $X_2Y_3$ where X is a cation with a +3 charge. What is the charge of the anion Y?
A sample of a compound containing carbon and hydrogen was burned in oxygen, producing 3.30 g of carbon dioxide ($CO_2$) and 1.35 g of water ($H_2O$). Determine what would be the empirical formula for the compound? (Molar masses: C = 12.01 g/mol, H = 1.01 g/mol, O = 16.00 g/mol)
A sample of a compound containing carbon and hydrogen was burned in oxygen, producing 3.30 g of carbon dioxide ($CO_2$) and 1.35 g of water ($H_2O$). Determine what would be the empirical formula for the compound? (Molar masses: C = 12.01 g/mol, H = 1.01 g/mol, O = 16.00 g/mol)
A compound is determined to be 62.58% carbon, 9.63% hydrogen, and 27.79% oxygen. A mass spectrum indicates that the molar mass is 154 g/mol. What is the molecular formula of this compound?
A compound is determined to be 62.58% carbon, 9.63% hydrogen, and 27.79% oxygen. A mass spectrum indicates that the molar mass is 154 g/mol. What is the molecular formula of this compound?
Flashcards
Chemical Formula
Chemical Formula
A shorthand way to show the types and amounts of atoms in a molecule.
Structural Formula
Structural Formula
Reveals how atoms connect in a molecule, showing the bonds between atoms.
Diatomic Molecules
Diatomic Molecules
Diatomic molecules have two atoms of the same element bonded together.
Ionic Compound Formula
Ionic Compound Formula
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Covalent Compound Formulas
Covalent Compound Formulas
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Empirical Formula
Empirical Formula
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Molecular Formula
Molecular Formula
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Empirical from Molecular
Empirical from Molecular
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Study Notes
Chemical Formulas
- Molecular formulas are short representations of molecules and compounds, displaying the types and number of atoms present
- These formulas use chemical symbols to indicate types of atoms, followed by subscripts showing the number of each type of atom
- Structural formulas also show how the atoms in a molecule are connected
- The subscript after the symbol indicates the number of atoms chemically bonded
- The number before the symbol indicates the number of separate atoms not bonded
- Formulas for metals, nonmetals, and inert gases are their chemical symbol
- Calcium is Ca
- Copper is Cu
- Bromine is Br
- Iodine is I
- Helium is He
- Neon is Ne
- Common gases and halogens are diatomic molecules with formulas written as a subscript of 2
- Hydrogen is H2
- Fluorine is Fl2
- Oxygen is O2
- Iodine is I2
- Nitrogen is N2
- Bromine is Br2
- Chlorine is Cl2
- For an ionic compound, the symbol for the positive ion (cation) comes first, followed by the negative ion (anion)
- Balance the positive and negative charges (valency) using the crisscross method to make the compound neutral
- Simplify subscripts to the simplest ratio of atoms in the compound
- Formulas for most covalent compounds show the actual number of atoms in the molecule
- Prefixes are used to indicate the number of atoms of an element in the molecule
- Mono is one
- Di is two
- Tri is three
- Tetra is four
- Penta is five
- Hexa is six
- Hepta is seven
- Octa is eight
- CO2 is carbon dioxide (2 oxygen atoms)
- CCl4 is carbon tetrachloride (4 chlorine atoms)
- N2O5 is dinitrogen pentoxide (2 nitrogen atoms, 5 oxygen atoms)
Empirical and Molecular Formula
- Empirical formulas indicate the types of atoms or ions present, shown in the simplest whole-number ratio
- Molecular formulas show the actual number of atoms present in the compound
- The empirical formula of a compound is obtained by reducing the molecular formula to simplest form
- Glucose (C6H12O16) has an atom ratio of 6:12:6
- Divided by 6 is 1:2:1
- Glucose's simplest forumla is CH2O
- Glucose (C6H12O16) has an atom ratio of 6:12:6
- If the actual ratios of atoms in a compound cannot be simplified, the molecular formula is the same as the empirical formula
- Multiple compounds share the same empirical formula
- C2H4 to CH2
- C3H6 to CH2
- C4H8 to CH2
- C5H10 to CH2
- C6H12 to CH2
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