Question 18M.3.sl.TZ2.3c.ii
| Date | May 2018 | Marks available | [Maximum mark: 1] | Reference code | 18M.3.sl.TZ2.3c.ii |
| Level | sl | Paper | 3 | Time zone | TZ2 |
| Command term | Calculate | Question number | c.ii | Adapted from | N/A |
Inductively Coupled Plasma (ICP) used with Mass Spectrometry (MS) or Optical Emission Spectrometry (OES) can be used to identify and quantify elements in a sample.
The following graphs represent data collected by ICP-OES on trace amounts of vanadium in oil.
Graph 1: Calibration graph and signal for 10 μg kg−1 of vanadium in oil
Graph 2: Calibration of vanadium in μg kg−1
[Source: © Agilent Technologies, Inc.1998. Reproduced with Permission, Courtesy of Agilent Technologies, Inc.]
Calculate, to four significant figures, the concentration, in μg kg−1, of vanadium in oil giving a signal intensity of 14 950.
[1]
«14 950 = 392.19x + 147.62»
x = 37.74 «μg kg–1»
Answer must be given to four significant figures.
Do not accept values obtained directly from the graph.
[1 mark]
