Intro to Chemistry: Step-by-Step Guidance for Worksheet Questions

Q1. What is 76 x 104 in standard notation?

Background

Topic: Scientific Notation

This question tests your ability to convert a number from scientific notation to standard (decimal) notation, a fundamental skill in chemistry for expressing very large or very small numbers.

Key Terms and Formulas

• Scientific Notation: A way of expressing numbers as a product of a coefficient and a power of ten, e.g., $a \times 10^n$.

• Standard Notation: The usual way of writing numbers without exponents.

Step-by-Step Guidance

1. Identify the coefficient and the exponent in the scientific notation. Here, the coefficient is 76 and the exponent is 4.

2. Recall that multiplying by $10^4$ means moving the decimal point 4 places to the right.

3. Write out the number 76 and add four zeros to the right, since there is no decimal part.

Try solving on your own before revealing the answer!

Q2. Write and balance the following chemical equation: Acid reacts with aqueous silver nitrate. What is the product?

Background

Topic: Chemical Reactions and Balancing Equations

This question tests your understanding of how to write and balance chemical equations, specifically for a reaction between an acid and silver nitrate in aqueous solution.

Key Terms and Formulas

• Reactants: The starting substances in a chemical reaction (here, an acid and silver nitrate).

• Products: The substances formed as a result of the reaction.

• Balancing Equations: Making sure the number of atoms of each element is the same on both sides of the equation.

Step-by-Step Guidance

1. Identify a common acid (for example, hydrochloric acid, HCl) and write the reactants: $\mathrm{HCl} (aq) + \mathrm{AgNO}_3 (aq)$.

2. Predict the products. When an acid reacts with silver nitrate, a double displacement reaction occurs, forming silver chloride (a precipitate) and nitric acid: $\mathrm{AgCl} (s) + \mathrm{HNO}_3 (aq)$.

3. Write the unbalanced equation: $\mathrm{HCl} (aq) + \mathrm{AgNO}_3 (aq) \rightarrow \mathrm{AgCl} (s) + \mathrm{HNO}_3 (aq)$.

4. Check the number of atoms of each element on both sides and adjust coefficients as needed to balance the equation.

Try solving on your own before revealing the answer!