4. How many moles of gold (Au) are in a pure gold nugget having a mass of 25.0 grams.

0.127 mol Au

Math

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Stoichiometry

Step 1: Define

[Given] 25.0 g Au

[Solve] moles Au

Step 2: Identify Conversions

[PT] Molar Mass of Au - 196.97 g/mol

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

0.126923 mol Au ≈ 0.127 mol Au

Explanation:

To convert from mass to moles, the molar mass must be used. This can be found on the Periodic Table.

Use this number as a ratio.

Multiply by the given number of grams.

Flip the fraction so the grams of gold will cancel.

The original measurement has 3 significant figures, so the answer must have the same. For the number we calculated that is the thousandth place. The 9 in the ten thousandth place tells us to round the 6 to a 7.

25.0 grams of gold is about 0.127 moles of gold.

11 players on a field that has a maximum of 11 players

the cold front replaces the warmer air at the ground level changing the wind to be breezy and denser.there is also an immediate drop in the temperature.