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3 years ago

Which are compounds, which are elements and which are mixtures?

Chemistry

1 answer:

Kamila [148]3 years ago

5 0

Answer:

first first row: element

second first row :compound

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The amount of radioactive carbon-14 in a sample is measured using a Geiger counter, which records each disintegration of an atom

sergij07 [2.7K]

Answer:

4121 years

Explanation:

From;

0.693/t1/2 = 2.303/t log No/N

t1/2= half life of the carbon-14

No= count rate of the living tissue

N= count rate of the sample

t = age of the sample

0.693/5730 =2.303/t log (13.5/8.2)

1.21 * 10^-4 = 2.303/t * 0.2165

1.21 * 10^-4 = 0.4986/t

t = 0.4986/1.21 * 10^-4

t = 4121 years

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3 years ago

2-phosphoglycerate(2PG) is converted to phosphoenolpyruvate (PEP) by the enzyme enolase. The standard free energy change(deltaGo

pogonyaev

Answer:

The correct option is: (D) -2.4 kJ/mol

Explanation:

Chemical reaction involved: 2PG ↔ PEP

Given: The standard Gibb's free energy change: ΔG° = +1.7 kJ/mol

Temperature: T = 37° C = 37 + 273.15 = 310.15 K (∵ 0°C = 273.15K)

Gas constant: R = 8.314 J/(K·mol) = 8.314 × 10⁻³ kJ/(K·mol) (∵ 1 kJ = 1000 J)

Reactant concentration: 2PG = 0.5 mM

Product concentration: PEP = 0.1 mM

Reaction quotient: $Q_{r} =\frac{\left [ PEP \right ]}{\left [ 2PG \right ]} = \frac{0.1 mM}{0.5 mM} = 0.2$

To find out the Gibb's free energy change at 37° C (310.15 K), we use the equation:

$\Delta G = \Delta G^{\circ } + 2.303 R T log Q_{r}$

$\Delta G = 1.7 kJ/mol + [2.303 \times (8.314 \times 10^{-3} kJ/(K.mol))\times (310.15 K)] log (0.2)$

$\Delta G = 1.7 + [5.938] \times (-0.699) = 1.7 - 4.15 = (-2.45 kJ/mol)$

Therefore, the Gibb's free energy change at 37° C (310.15 K): ΔG = (-2.45 kJ/mol)

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3 years ago

Balance the equation. SiO2 + CaC2 → Si + CaO + CO2

Sunny_sXe [5.5K]

Co2 is oxygen because that what you took to ask ppl for

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3 years ago

How many moles of water produced from 13.5 mol of oxygen

skad [1K]

Answer:

diffrent types of maks and modles

Explanation:

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2 years ago

Which of the following interactions can contribute to the intrinsic binding energy during enzymatic catalysis? choose all that a

Lady_Fox [76]

1. electrostatic interactions
3. van de waals interactions 
4. hydrogen bonding

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3 years ago

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