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3 years ago

Where should the author of a case study introduce the central question of the text?

Chemistry

2 answers:

Contact [7]3 years ago

8 0

Answer:

Explanation:

Shtirlitz [24]3 years ago

7 0

Answer:

B. at the beginning

Explanation:

i took the test

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You wish to prepare a tape-casting slip containing 50 vol% Al2O3 and 50 vol% polyvinyl butyral (PVB) binder. If the density of A

belka [17]

Answer: The mass of PVB required to produce 1000 grams of tape is 213.4 grams

Explanation:

To calculate the mass of aluminium oxide, we use the equation:

$\text{Density of substance}=\frac{\text{Mass of substance}}{\text{Volume of substance}}$ .......(1)

For $Al_2O_3$

We are given:

50% (v/v) of $Al_2O_3$

This means that 50 mL of aluminium oxide is present in 100 mL of tape

Calculating the mass of aluminium oxide by using equation 1:

Density of aluminium oxide = $3.98 g/cm^3$

Volume of aluminium oxide = $50mL=50cm^3$ (Conversion factor: $1mL=1cm^3$ )

Putting values in equation 1, we get:

$3.98g/cm^3=\frac{\text{Mass of aluminium oxide}}{50cm^3}\\\\\text{Mass of aluminium oxide}=(3.98g/cm^3\times 50cm^3)=199g$

Mass of aluminium oxide = 199 g

For PVB:

We are given:

50% (v/v) of PVB

This means that 50 mL of PVB is present in 100 mL of tape

Calculating the mass of PVB by using equation 1:

Density of PVB = $1.08 g/cm^3$

Volume of PVB = $50mL=50cm^3$

Putting values in equation 1, we get:

$1.08g/cm^3=\frac{\text{Mass of PVB}}{50cm^3}\\\\\text{Mass of PVB}=(1.08g/cm^3\times 50cm^3)=54g$

Mass of PVB = 54 g

Mass of tape = Mass of aluminium oxide + mass of PVB

Mass of tape = [199 + 54] g = 253 g

To calculate the mass of PVB required to produce 1000 g of tape, we use unitary method:

When 253 grams of tape is made, the mass of PVB required is 54 g

So, when 1000 grams of tape is made, the mass of PVB required will be = $\frac{54}{253}\times 1000=213.4g$

Hence, the mass of PVB required to produce 1000 grams of tape is 213.4 grams

4 0

3 years ago

An atom of 125Sn has a mass of 124.907785 amu. Calculate the binding energy in MeV per atom. Use the masses: mass of 1H atom = 1

Ksenya-84 [330]

Answer:

1.06×10³ MeV/atom

Explanation:

Atomic number : It is defined as the number of electrons or number of protons present in a neutral atom.

Also, atomic number of Sn = 5 0

Thus, the number of protons = 50

Mass number is the number of the entities present in the nucleus which is the equal to the sum of the number of protons and electrons.

Mass number = Number of protons + Number of neutrons

125 = 50 + Number of neutrons

Number of neutrons = 75

Mass of neutron = 1.008665 amu

Mass of proton = 1.007825 amu

Calculated mass = Number of protons*Mass of proton + Number of neutrons*Mass of neutron

Thus,

Calculated mass = (50*1.007825 + 75*1.008665) amu = 126.041125 amu

Given mass = 124.907785 amu

Mass defect = Δm = |126.041125 - 124.907785| amu = 1.13334 amu

The conversion of amu to MeV is shown below as:-

1 amu = 931.5 MeV

So, Energy = 1.13334*931.5 MeV/atom = 1.06×10³ MeV/atom

3 0

3 years ago

Consider a generic redox reaction?

vesna_86 [32]

The Nernst equation allows us to predict the cell potential for voltaic cells under conditions other than the standard conditions of 1M, 1 atm, 25°C. The effects of different temperatures and concentrations may be tracked in terms of the Gibbs energy change ΔG. This free energy change depends upon the temperature & concentrations according to ΔG = ΔG° + RTInQ where ΔG° is the free energy change under conditions and Q is the thermodynamic reaction quotient. The free energy change is related to the cell potential Ecell by ΔG= nFEcell

so for non-standard conditions
-nFEcell = -nFE°cell + RT InQ

or

Ecell = E°cell - RT/nF (InQ)

which is called Nernst equation.

5 0

3 years ago

How do you use the changes in the phase of water to keep you cool?

sineoko [7]

Answer:

by freezing

Explanation:

8 0

3 years ago

How many of the zeros in the measurement 0.050060 are significant

Feliz [49]

I think 3 of them are its been 1 half years since ive done this i dont take chemistry anymore