ipl-logo

Explain Why Mg Has A Higher Melting Point Than Na.

1142 Words5 Pages

Type 1: metal vs metal
Example: Explain why Mg has a higher melting point than Na.
Reason: Compare the number of delocalized electrons.

Type 2: ionic compound vs ionic compound
Example: Explain why NaF has a higher melting point than NaCl.
Reason: Compare lattice energy.

Type 3: simple molecule vs simple molecule
Example: Explain why H2O has a higher melting point than H2S.
Reason: Compare the relative strength of the intermolecular forces.

Type 4: ionic compound vs simple molecule
Example: Explain why NaCl has higher melting point than H2O.
Reason: Compare ionic bond strength with weak intermolecular forces.

Type 5: giant molecule vs simple molecule
Example: Explain why SiO2 has a higher melting point than H2O.
Reason: …show more content…

As it is the same for all gases, R is also called the universal gas constant.
R = 8.31 J K-1 mol-1
Assuming a gas sample to be under ideal conditions, the value of R can be determined by measuring its volume, temperature and pressure and substituting the values into the ideal gas equation.
Consider one mole of a gas at standard temperature and pressure (s.t.p).
E.g., P = 101 325 Pa, V = 22.4 x103 m3, n = 1 mol and T = 273.15 K
Using PV = nRT,

R = PV/nT = ((101325)(0.0224))/((1)(273.15)) = 8.31 J K-1 mol-1

Experimental Determination of the Molar Gas Constant

When magnesium is added to an aqueous solution of hydrochloric acid, the following reaction occurs:
Mg(s) + 2HCl(aq)  MgCl2(aq) + H2(g)
Preliminary Calculation (to determine the amount of reactants to be used)
With a graduated gas syringe of 100 cm3 capacity, assume that 80.0 cm3 of H2 gas is collected.

no. of moles of H2 gas = 80/24000 mol = no. of moles of Mg

mass of Mg = 80/24000 x 24.1 = 0.0803 g

Let the concentration of HCl(aq) used be 0.500 mol dm-3.

no. of moles of HCl = 80/24000 x 2

Show More
Related
993 Words | 4 Pages

Question3: Experiment 3 The unknown acid sample was 1 • Monoprotic Acid Trails Initial NaOH solution (mL) final NaOH solution (mL) The volume of NaOH to titrate the acid (mL) Amount of Unknown Acid sample 1 (g) The moles of the Unknown Acid (mol) Molar mass of the Unknown Acid (g/mol) A 3.38 28.31 24.93 0.150 0.0026 57.69 B 0.18 29.32 29.14 0.175 0.0029

Read More
1066 Words | 5 Pages

Green with a silver nitrate (AgNO3) solution. Assuming that certain amounts of AgNO3 was dissolved in a particular amount of water to produce the solution. Find out how many moles of Na2CO3 were involved in the silver nitrate reaction first. To my knowledge of Mr. Green’s addition of 1.5 grams of Na2CO3 to the silver nitrate solution comes from the statement. Since Na2CO3 has a molar mass of 105.99 g/mol, the amount of Na2CO3 is: moles of Na2CO3 = mass / molar mass moles of Na2CO3 = 1.5 g / 105.99 g/mol moles of Na2CO3 = 0.0141 mol

Read More
904 Words | 4 Pages

It can be hypothesized that the water in the product affected the melting point

Read More
302 Words | 2 Pages

A two-hundred and fifty milliliter(ml) flask was zeroed out on the scale. Fifty milliliters of HCl was put into the flask and weighed. The unknown mixture was poured into the HCl while

Read More
1525 Words | 7 Pages

In order to find the amount of a product made during a double displacement reaction, the product has to be separated from the solution. From this number of moles of precipitate can be calculated. From there the number of moles of reactants can be calculated using the mole ratios of the particular reaction that occurred. As seen in Table 5 it is shown that by finding out the number of moles of the unknown, the molar mass of the unknown can be calculated. From the found mass of the unknown compound, the mound of the original ion can be found.

Read More
647 Words | 3 Pages

Post Lab Questions: 2Mg + O2 →2MgO 0.29gMg 1molMg24.312molMgO2molMg100= 4.40molMgO ←theoretical yield 2Mg + O2 → 2MgO →2/24 =

Read More
1866 Words | 8 Pages

If one wanted to find the volume of mole this gas at STP, then all that is required is to divide the 0.0377 liters at STP by the original number of moles of magnesium from the start of the experiment; this would yield the results at STP if one mole of magnesium was reacted, which is the same as one mole of hydrogen produced according to the chemical equation. In the end, the volume of mole of the hydrogen gas produced in this experiment would be equal to 23.6

Read More
1328 Words | 6 Pages

Which of the following unit is used to indicate mass? a. Cm3 b. Um c. Mg d. mL 21. Which of the following demonstrate a chemical reaction of water?

Read More
1105 Words | 5 Pages

This number was found by dividing the 0.282 g by the number of moles of NaOH, 0.00201 moles (which was found by dividing the 20.1 mL used by 1000 and multiplying that number by the 0.1 M concentration). The molecular weight data can be used to compare and identify experimental data to that of known data in order to identify the unknown. The known molecular weight of benzoic acid is 122.12 g/mol, so there were errors in obtaining the molecular weight from the lab as the lab molecular weight is almost 20 g/mol higher. These errors could have been caused by impurities remaining in the final product such as the previously used/present magnesium, iodine, or the original

Read More
729 Words | 3 Pages

Using the Law of Definite Proportions, the mass of this product was used to determine the number of moles of copper and chlorine in the sample, which led to being able to determine the

Read More
1234 Words | 5 Pages

The melting point of sulphur is 112.8 °C and the boiling point of Sulphur is 444.6 °C. Sulphur has an equal number of proton and neutron due to its atomic mass subtracted by the proton/atomic number. Sulphur

Read More
1118 Words | 5 Pages

10 g b. 12 g c. 9 g How many moles are there in 235 g CaCO3? 235 mol b. 23 mol c. 2.35 mol How many moles are there in C2H2? 1.07 mol b. 1 mol c. 0.227 mol 10. How many grams of magnesium are there in 7.52 mol MgO?

Read More
902 Words | 4 Pages

Also, salt is an ionic compound and not a polar covalent compound, even though it did not melt last, due to the fact that the elements Na and Cl, both lose or gain an electron and then bond because of their opposite charges, which is a property only ionic bonds possess. The wax was the only substance whose results were synonymous with my hypothesis, since it required a low temperature for its melting point and was not soluble in water, both properties of nonpolar covalent compounds. Potential sources of error included not labeling the spots each substance was placed in the aluminum foil boat, seeing as the result for sugar seemed to be the correct conclusion for salt and vice versa. A future experiment would involve individually testing each substance in an aluminum foil boat, of the same brand, on a heat plate in order to avoid uncertainty. Each substance should be timed to record the precise time each substance began to melt or burn.

Read More
1001 Words | 5 Pages

Procedure A. Preparation of NaOH solution The molarity of a solution is the ratio of the number of solutes dissolved in a liter of solution. To figure out the needed mass (in grams) of NaOH pellets to be dissolved in a 0.25 L of water, remember that a mole is equivalent to the quotient of mass over the molar mass of the substance. This was used to rearrange the base formula and to derive the mathematical equation of mass in terms of molarity. mass (g) =

Read More
822 Words | 4 Pages

Introduction: Melting is the change of a solid into a liquid when heat is applied. Melting will occur at a fixed temperature which known as melting point. Melting point is the temperature at which the solid and liquid forms of a pure substance can exist in equilibrium. The temperature will increase until the melting point is reached when heat is applied. Heat will convert the solid into a liquid with no temperature change.

Read More

More about Explain Why Mg Has A Higher Melting Point Than Na.

Related Topics

Open Document