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4 years ago

What are superconductors

Chemistry

1 answer:

NNADVOKAT [17]4 years ago

8 0

Super conductors are metals that let electricity flow through them easily

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Elimination of the pharmaceutical IV antibiotic gentamicin follows first-order kinetics. If the half-life of gentamicin is 1.5 h

Genrish500 [490]

Explanation:

The given data is:

The half-life of gentamicin is 1.5 hrs.

The reaction follows first-order kinetics.

The initial concentration of the reactants is 8.4 x 10-5 M.

The concentration of reactant after 8 hrs can be calculated as shown below:

The formula of the half-life of the first-order reaction is:

$k=\frac{0.693}{t_1_/_2}$

Where k = rate constant

t1/2=half-life

So, the rate constant k value is:

$k=\frac{0.693}{1.5 hrs}$

The expression for the rate constant is :

$k=\frac{2.303}{t} log \frac{initial concentration}{concentration after time "t"}$

Substitute the given values and the k value in this formula to get the concentration of the reactant after time 8 hrs is shown below:

$\frac{0.693}{1.5 hrs} =\frac{2.303}{8 hrs} x log \frac{8.4x10^-^5}{y} \\ log \frac{8.4x10^-^5}{y} =1.604\\\frac{8.4x10^-^5}{y}=10^1^.^6^0^4\\\frac{8.4x10^-^5}{y}=40.18\\y=\frac{8.4x10^-^5}{40.18} \\=>y=2.09x10^-^6$

Answer: The concentration of reactant remains after 8 hours is 2.09x10^-6M.

5 0

3 years ago

The chemical formula for beryllium oxide is BeO.A chemist determined by measurements that 0.045 moles of beryllium participated

blondinia [14]

Answer: 0.405g

Explanation:

Molar Mass of Be = 9g/mol

Number of mole of Be = 0.045mol

Mass conc. Of Be = 0.045 x 9 = 0.405g

8 0

4 years ago

Calculate the atomic mass for copper using the weighted average mass method. Express your answer using two decimal places and in

tatuchka [14]

Answer:

63. 55 amu

Explanation:

Copper is known to exist in two different isotopes which are Cu-63 and Cu-65.

Cu-63 has an atomic mass of 62.93 amu and it has an abundance of 69.15%.

Similarly,

Cu-65 has an atomic mass of 64.93 amu and it has an abundance of 30.85%

Therefore, using the weighted average mass method, the atomic mass of copper is:

Atomic mass of copper = (0.6915*62.93) amu + (0.3085*64.93) amu = 43.52 amu + 20.03 amu = 63.55 amu

Thus, the atomic mass of copper (express in two decimal places) is 63.55 amu

8 0

4 years ago

Need to complete the chart

GalinKa [24]

Answer:

Row 1

$[H^+]=1.8\times 10^{-6}M$

$pH=-\log[H^+]=-\log[1.8\times 10^{-6}]=5.7$

pOh=14-pH=14-5.7=8.3

$pOH=-\log[OH^-]$

$[OH^-]=0.5\times 10^{-8}M$

Hence, acidic

Row 2

$[OH^-]=3.6\times 10^{-10}M$

$pOH=-\log[OH^-]=-\log[3.6\times 10^{-10}]=9.4$

pH=14-pOH=14 - 9.4 = 4.6

$pH=-\log[H^+]$

$[H^+]=2.6\times 10^{-5}M$

Hence, acidic

Row 3

pH = 8.15

$[H^+]=0.7\times 10^{-8}M$

pOH=14-pH=14 - 8.15 = 5.8

$pOH=-\log[OH^-]$

$[OH^-]=1.5\times 10^{-6}M$

Hence, basic

Row 4

pOH = 5.70

$[OH^-]=1.8\times 10^{-6}M$

pH=14-pOH=14 - 5.70 = 8.3

$pH=-\log[H^+]$

$[H^+]=0.5\times 10^{-8}M$

Hence, basic

3 0

4 years ago

Which type of energy refers to the sum of potential and kinetic energies in the particles of a substance?

Andru [333]

Thermal (heat) energy is ur answer mate

Hope it helps

5 0

4 years ago