How many moles is 287.7 grams of Iridium (Ir)?

1.497 mol Ir

General Formulas and Concepts:

Math

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right

Chemistry

Atomic Structure

Reading a Periodic Table

Stoichiometry

Using Dimensional AnalysisExplanation:

Step 1: Define

287.7 g Ir

Step 2: Identify Conversions

[PT] Molar Mass of Ir - 192.22 g/mol

Step 3: Convert

Set up:                                 Multiply/Divide:                  

Step 4: Check

Follow sig fig rules and round. We are given 4 sig figs.

1.49672 mol Ir ≈ 1.497 mol Ir

Explanation:

To convert from grams to moles, we must the molar mass of iridium, which can be found on the Periodic Table.

Ir: 192.22 g/mol

Use the molar mass as a ratio.

Multiply by the given number of grams: 287.7

Flip the fraction so the grams of Iridium will cancel.

Divide.

The original measurement has 4 significant figures, so we must round our answer to 4 sig figs as well. For the answer we calculated, that is the thousandth place.

The 7 in the ten thousandth place tells us to round the 6 up to a 7.

There are about 1.497 moles of iridium in 287.7 grams.

If it isn’t a then it has to be d idk tho cause there’s no picture

The answer is b because c don't explain why the moths are on them and it isn't a because as we know only one species of moth does this