.NET Fiddle

CSharp · Console

/Program.cs

using System;
					
public class Program
{
	public static void Main()
	{
		string test = "0.1542 Mol";
		string[] testParts = test.Split(' '); 
		string rounded = $"{Convert.ToDecimal(testParts[0]):0.00} {testParts[1]}";
		Console.WriteLine(rounded);
	}
}