Molecules are packed tigghtly together

Energy from a reaction was determined to be 3870 J using a water calorimeter, when burning 9.00 grams of H2. What is the total

Paraphin [41]

Answer:

860 J / mol

Explanation:

Enthalpy = Energy / no. of moles

no. of moles = mass / molar mass

Take the atomic mass of H = 1.0,

molar mass of H2 = 1.0 x 2

= 2.0

no. of moles of H2 = 9.00/2

= 4.5 mol

Hence,

Enthalpy = 3870 / 4.5

=860 J / mol

7 0

4 years ago

Compute diffusion coefficients for the interdiffusion of carbon in both (a) α-iron (BCC) and (b) γ-iron (FCC) at 800.˚C. Assume

Ne4ueva [31]

Answer:

a)1.404 E-10 m^2/s

b)1.438 E-12 m^2/s

Explanation:

Diffusion Coefficients can be calculated at different temperatures taking into account the energy of the diffusive process, remember that this process takes place in the interstices of the solid, and gets with higher temperatures due to the higher kinetic energy of the particles.

$D=D_{o} *exp(-Q/RT)$

a) For α-iron (BCC)

$D=1.10*10^{-6} m^{2}/s *exp(-80.0kJ/mol/8.314*10^{-3}kJ/mol*k*1073.15K)= 1.404*10^{-10} m^{2}/s$

b) For γ-iron (FCC)

$D=2.30*10^{-5} m^{2}/s *exp(-148.0kJ/mol/8.314*10^{-3}kJ/mol*k*1073.15K)= 1.438*10^{-12} m^{2}/s$

5 0

3 years ago

C.Convert the following using the molar mass of each:

Alik [6]

Answer:

1. 1.145 mole

2. 19.368g

3. 66.67 moles

4. 0.0056g

Explanation:

The following calculations gives the answers to the various questions asked above:

1. Molar mass of NaCl = 23 + 35.5 = 58.5g/mol

Mass of NaCl from the question = 67g

Number of mole NaCl =.?

Number of mole = Mass /Molar Mass

Number of mole NaCl = 67/58.5

Number of mole of NaCl = 1.145 mol

2. Number of mole of H2O = 1.076 mole

Molar Mass of H2O = (2x1) + 16 = 2 + 16 = 18g/mol

Mass of H2O =?

Mass = number of mole x molar Mass

Mass of H2O = 1.076 x 18

Mass of H2O = 19.368g

3. Molar mass of C6H12O6 = (12x6) + (12x1) + (16x6) = 72 + 12 + 96 = 180g/mol

Mass of C6H12O6 = 1.2x104g

Mole of C6H12O6 =.?

Number of mole = Mass /Molar Mass

Mole of C6H12O6 = 1.2x104/180

Mole of C6H12O6 = 66.67 moles

4. Molar mass of Br2 = 2 x 80 = 160g/mol

Mole of Br2 = 3.5x10^-5 moles

Mass of Br2 =?

Mass = number of mole x molar Mass

Mass of Br2 = 3.5x10^-5 x 160

Mass of Br2 = 5.6x10^-3 = 0.0056g

4 0

3 years ago

Read 2 more answers

Which factor most influenced the economic

Vikki [24]

It was by far "warm and wet growing seasons" that was the most important factor in terms of the South's economic development. Cotton and tobacco were the biggest exports.

Explanation:

These crops created tons of cash, had massive markets round the world, however required a stable and enormous hands to grow and harvest them.The yank South is understood for its long, hot summers, and wealthy soils in stream valleys creating it a perfect location for growing cotton. the various southern seaports and riverside docks allowed shipping cotton to remote destinations. By 1860, Southern plantations equipped seventy fifth of the world's cotton, with shipments from Houston, city, Charleston, Mobile, Savannah, and some different ports. The unquenchable European demand for cotton was a results of the commercial Revolution that created the machinery and factories to method raw cotton into vesture that was higher and cheaper than hand-made product.

6 0

4 years ago

Read 2 more answers

Consider the preparation of methyl benzoate by reacting benzoic acid with methanol using sulfuric acid as a catalyst. Reaction s

Ronch [10]

Answer:

See explanation

Explanation:

The molecular mass is the sum of the relative atomic masses of all the atoms in the molecule.

The relative atomic mass of reactants and products are calculated as follows;

Benzoic acid is C7H6O2 hence the molar mass of benzoic acid is ;

7(12) + 6(1) + 2(16) = 84 + 6 + 32 = 122.0 g/mol

Methyl benzoate is C8H8O2

8(12) + 8(1) + 2(16) = 96 + 8 + 32 = 136.0 g/mol

7 0

3 years ago