A cylinder contains 68 g of ammonia at STP.
How many moles of ammonia are present in this cylinder?

Explanation

To find the number of moles of ammonia (NH₃) present in a cylinder containing 68 g of ammonia at STP, we can follow these steps:

### Step 1: Identify the given data
- Mass of ammonia (NH₃) = 68 g

### Step 2: Calculate the molar mass of ammonia (NH₃)
- The molar mass of NH₃ can be calculated by adding the atomic masses of nitrogen (N) and hydrogen (H).
- Atomic mass of nitrogen (N) = 14 g/mol
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