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3 years ago

ILL GIVE BRAINLIST!!!!!!

Chemistry

2 answers:

attashe74 [19]3 years ago

7 0

Answer:

the investigation and results are more reliable if the results can be reproduced.

Explanation:

As you may already know, a scientific experiment is a set of procedures performed by a scientist who seeks to find answers to a particular phenomenon or situation. Every experiment, therefore, generates a result that seeks to explain a certain thing.

It is common and even recommended that scientists reproduce each other's experiments. This is because if, for example, an experiment done by me results in the same conclusions as an experiment done by you a few years ago, it means that the results of our experiments are credible and that they can be considered as correct and true.

fomenos3 years ago

3 0

hope this helpssss :)

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Using the information in the table, calculate the number of moles in a \pu{7.89 kg}7.89 kg7, point, 89, space, k, g sample of as

Karolina [17]

We have to find the number of moles in a 7.89 kg sample of aspirin.

The formula of aspirin is: C₉H₈O₄

We are given the molar mass of C, H and O:

H: 1.008 g/mol C: 12.01 g/mol O: 16.00 g/mol

Since one molecule of aspirin has 9 atoms of C, 8 atoms of H and 4 atoms of O, and using the molar masses given, we can calculate the molar mass of aspirin:

molar mass of aspirin = 9 * 12.01 g/mol + 8 * 1.008 g/mol + 4 * 16.00 g/mol

molar mass of aspirin = 180.154 g/mol

Before we find the number of moles we can convert 7.89 kg to g. Since we know that there are 1000 g in 1 kg, we can convert it like this:

1000 g = 1 kg

mass of sample = 7.89 kg * 1000 g/1 kg

mass of sample = 7890 g

Finally, we can find the number of moles in the sample using the molar mass.

number of moles = 7890 g * 1 mol/180.154 g

number of moles = 43.795 moles

Answer: The number of moles in the sample is 43.8 moles (using 3 SF)

7 0

1 year ago

Calculate the energy (in J/atom) for vacancy formation in silver, given that the equilibrium number of vacancies at 800 C is 3.6

MAXImum [283]

Answer:

the energy vacancies for formation in silver is $\mathbf{Q_v = 3.069*10^{-4} \ J/atom}$

Explanation:

Given that:

the equilibrium number of vacancies at 800 °C

i.e T = 800°C is 3.6 x 10¹⁷ cm3

Atomic weight of sliver = 107.9 g/mol

Density of silver = 9.5 g/cm³

Let's first determine the number of atoms in silver

Let silver be represented by N

SO;

$N = \dfrac{N_A* \rho _{Ag}}{A_{Ag}}$

where ;

$N_A =$ avogadro's number = $6.023*10^{23} \ atoms/mol$

$\rho _{Ag}$ = Density of silver = 9.5 g/cm³

$A_{Ag}$ = Atomic weight of sliver = 107.9 g/mol

$N = \dfrac{(6.023*10^{23} \ atoms/mol)*( 9.5 \ g/cm^3)}{(107.9 \ g/mol)}$

N = 5.30 × 10²⁸ atoms/m³

However;

The equation for equilibrium number of vacancies can be represented by the equation:

$N_v = N \ e^{^{-\dfrac{Q_v}{KT}}$

From above; Considering the natural logarithm on both sides; we have:

$In \ N_v =In N - \dfrac{Q_v}{KT}$

Making $Q_v$ the subject of the formula; we have:

${Q_v = - {KT} In( \dfrac{ \ N_v }{ N})$

where;

K = Boltzmann constant = 8.62 × 10⁻⁵ eV/atom .K

Temperature T = 800 °C = (800+ 273) K = 1073 K

$Q _v =-( 8.62*10^{-5} \ eV/atom.K * 1073 \ K) \ In( \dfrac{3.6*10^{17}}{5.3 0*10^{28}})$

$\mathbf{Q_v = 2.38 \ eV/atom}$

Where;

1 eV = 1.602176565 × 10⁻¹⁹ J

Then

$Q_v = (2.38 \ * 1.602176565 * 10^{-19} ) J/atom }$

$\mathbf{Q_v = 3.069*10^{-4} \ J/atom}$

Thus, the energy vacancies for formation in silver is $\mathbf{Q_v = 3.069*10^{-4} \ J/atom}$

8 0

3 years ago

Cl2 + AlBr3 → AlCl3 + Br2How many grams of Cl2 are needed to produce 19.03g of AlCl3?

VladimirAG [237]

Answer:

14.89 g

Explanation:

Please see the step-by-step solution in the picture attached below.

Hope this answer can help you. Have a nice day!

5 0

3 years ago

The dissolution of ammonium nitrate occurs spontaneously in water at 25°C. As NH4NO, dissolves, the temperature of the water dec

MA_775_DIABLO [31]

Answer:

ΔG <0 , ΔH > 0 , ΔS > 0 .

Explanation:

From the data given in question , the reaction is a spontaneous process , hence , the value of change in gibbs free energy would be negative , ΔG <0

And , on dissolution process , the temperature of the water decreases , i.e. , it is an endothermic process , i.e. , the change in enthalphy value is positive , ΔH > 0

And , during the process of dissolution , the ammonia salt break does to ions , i.e. , the randomness increases , hence the ΔS > 0

6 0

3 years ago

What mass of C6H8O7 should be used every 7.0 X 10^2mg NaHCO3

Savatey [412]

Mass C₆H₈O₇ : 0.531484 g

<h3>Further explanation</h3>

Reaction

3NaHCO₃ (aq) + C₆H₈O₇ (aq) → 3 CO₂ (g) + 3 H₂O (l) + Na₃C₆H₅O₇ (aq)

MW NaHCO₃ : 84 g/mol

mass NaHCO₃ : 7.10² mg=0.7 g

mol NaHCO₃ :

$\tt mol=\dfrac{0.7}{84}=0.0083$

mol C₆H₈O₇ :

$\tt \dfrac{1}{3}\times 0.0083=0.00277$

MW C₆H₈O₇ : 192 g/mol

mass C₆H₈O₇ :

$\tt mass=0.00277\times 192=0.53184$

4 0

2 years ago