There are 2.60 1015 short tons of oxygen in the atmosphere (1 short ton = 2000 lb). How many metric tons of oxygen are present (1 metric ton = 1000 kg)?

This is just a simple conversion.

2.60\times\10^{15}\,short \,tons \, \times \, \frac {x\,metric\,tons}{y\,short\,tons}=2.60\times\10^{1 5}\,\times\,\frac xy\,metric\,tons

So, where do you get the conversion factor? Let me google that for you. (http://www.lmgtfy.com/?q=convert+metric+ton+to+long+ton)

If I have 1g/ 30ml of a solution and I take out 5ml of that what is the concentration of the 5mL?

If I have 1g/ 30ml of a solution and I take out 5ml of that what is the concentration of the 5mL?


Please post new questions in new threads.

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The concentration is a property of the solution as a whole. If the concentration is 1g/30 ml,

\frac {1\,g}{30\,mL}=0.033333\,\frac {g}{mL}

regardless of how much you took.

If the question what is the mass of material that was taken, then

5\,mL\,\times\,\frac {1\,g}{30\,mL}=5\,mL\,\times\,0.033333\,\frac {g}{mL}= 0.166667\,g