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pogonyaev
3 years ago
7

Which of these measurements is expressed as three significant figures?

Chemistry
1 answer:
kipiarov [429]3 years ago
6 0

Which of these measurements is expressed as three significant figures?  


C. 4.20 g


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. Un cuerpo irregular se introduce dentro de una probeta que inicialmente tiene un volumen de 20 ml como muestra la figura Despu
MrMuchimi

Answer:

El volumen del cuerpo es el mismo al comienzo de la experiencia.

Explicación:

El volumen del cuerpo es el mismo al principio porque el volumen no cambia si la temperatura permanece igual. Si cambiamos la temperatura i. mi. Al aumentar la temperatura, las moléculas comienzan a expandirse y se produce un aumento de volumen mientras que cuando disminuimos la temperatura, las moléculas de esa sustancia comienzan a contraerse y el volumen de esa sustancia disminuye. Entonces concluimos que el volumen depende de la temperatura.

6 0
2 years ago
What is the ph of a 0.25 m solution of c6h5nh2 given that its kb is 1.8 x 10-6?
IrinaK [193]

The pH a 0.25 m solution of C₆H₅NH₂ is equal to 3.13.

<h3>How do we calculate pH of weak base?</h3>

pH of the weak base will be calculate by using the Henderson Hasselbalch equation as:

pH = pKb + log([HB⁺]/[B])

pKb = -log(1.8×10⁻⁶) = 5.7

Chemical reaction for C₆H₅NH₂ is:

                          C₆H₅NH₂ + H₂O → C₆H₅NH₃⁺ + OH⁻

Initial:                     0.25                           0            0

Change:                    -x                             x             x

Equilibrium:        0.25-x                           x             x

Base dissociation constant will be calculated as:
Kb = [C₆H₅NH₃⁺][OH⁻] / [C₆H₅NH₂]

Kb = x² / 0.25 - x

x is very small as compared to 0.25, so we neglect x from that term and by putting value of Kb, then the equation becomes:

1.8×10⁻⁶ = x² / 0.25

x² = (1.8×10⁻⁶)(0.25)

x = 0.67×10⁻³ M = [C₆H₅NH₃⁺]

On putting all these values on the above equation of pH, we get

pH = 5.7 + log(0.67×10⁻³/0.25)

pH = 3.13

Hence pH of the solution is 3.13.

To know more about Henderson Hasselbalch equation, visit the below link:
brainly.com/question/13651361

#SPJ4

5 0
2 years ago
an atom of which element has the strongest attraction for electons in a chemical bond?cholorine, phosphorus, carbon, sulfur
vredina [299]

Answer:

D) Sulphur

Explanation:

Sulphur has the strongest electromagnetivity here

7 0
2 years ago
I need the answers to this and to see if what I put is right so far
klemol [59]

1) B+3 is ok. The exercise already put B+3. What

-------------------------------------------------------------------------------------------------------------------

2) Ge is a neutral atom because it doesn't have any charge.

Germanium has 32 electrons and 32 protons because its atomic number is 32.

Be careful with that.

Neutral atoms have the same numbers of electrons and protons.

-------------------------------------------------------------------------------------------------------------------

3)

5 0
8 months ago
X: glucose + oxygen ---- carbon dioxide + water
elena-s [515]

Answer:

X

Explanation:

5 0
1 year ago
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