Chemistry Lab Report from the 19th December 2011 Introduction In the chemistry lab on Monday the 19th December 2011, we were supposed to recognize that different salts can change the colour(s) of a flame. We gave with each salt a little ethanol (just as much that the floor of the petri dish was covered

EE2901S Lab report Lab 3: Use of NAND Gates
L. Kok Ming Ariel 13066708D 14/04/2015
Introduction All
possible logic circuits can be produced by combining basic AND, OR
and NOT gates. However, most commercially available logic gates do
not readily perform all the AND, OR and NOT operations in a

Lab Report The effect of rising temperature on the rate of a reaction ---- L. C. , MYP4B Science --- Background Information The rate of reaction depends on the temperature and concentration of the reactants involved in a reaction, as well as the surface area of solid reactants. It can be measured in two

Table 1 shows all the raw data that collecting in the lab. The last column: p×V is calculated for the following calculation. During this experiment, there’s obvious outlier which happens in Table 1 and causes the following calculations all wrong.

Compare to group of 3cm and 5cm Mg, the group of 4cm Mg has wrong data for the volume of H_{2} measured, which steady in about 10mL (0.01L). But have disproportionate mass and pressure. For group of 5cm Mg, although the errors are not so obvious, the volumes of H_{2} may have some problems in measuring since the volumes are relative low compare to other groups and finally cause the average value of molar volume of H_{2} is not close to the theoretical value that about 22.7mol/L.

For Table 2, R is a constant that using in the calculation directly. T is the room temperature in form of Kelvin. p×V uses the previous calculated data. According to the formula pV=nRT, n=.

To make sure the following calculations are as previse as possible, I make the n has 6 significance digit, which one more time than the usual one. For Table 3, the significance digits are all more than common ones. I use 5 significance digit here since the final ones are relative high which means that less significance digit can also shows .....[read full text]

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In this investigation, the aim is to determine the molar volume of H_{2}. According to Avogadro’s hypothesis that equal volumes of all gases contain equal numbers of molecules under the same conditions of temperature and pressure. So, if I can determine the mass of Mg, I can get the number of moles of Magnesium and the number of moles of H_{2}. The chemical formula is:

Mg + 2HCl → MgCl_{2}+ H_{2}

From the calculation, we could know that the experimental value of the molar volume of H_{2} is 20.643 L/mol, which is relatively smaller compare to the theoretical value 22.7 L/mol. If I delete one suspected group of data again, the data will closer to the theoretical value. The average sum uncertainty in this experiment is only 10.819%, which means that the general outcome is accurate.

In this investigation, the Molar Volume of H_{2} is measured by a different method than the Task sheet provided. I determine the mass of Mg, the volume and the pressure of H_{2} and the temperature, which are necessary for the ideal gas law. All the necessary data are .....

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