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3 years ago

You estimate that you sent 135 texts last week but when you get the bill, it was actually 175. Calculate the percent error

Chemistry

1 answer:

FinnZ [79.3K]3 years ago

6 0

Answer: -40

Explanation: Percent error is calculated by subtracting the value you actually recieved from the literature value (175 in your case) SO your answer should be 135-175=-40.

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A student finds the mass of a solid object to be 45.026 grams. The student places some water in a graduated cylinder as shown in

Aleks04 [339]

I think it we’ll be 17088 bc

8 0

3 years ago

If a diatomic molecule has a vibrational force constant of k=240 kg s-2 and a reduced mass of 1.627x10-27 kg, its vibrational fr

asambeis [7]

Answer:

2040 cm-1

Explanation:

The vibrations frequency is obtained from;

v=1/2πc √k/μ

Where;

k= force constant = 240kgs-2

μ= reduced mass = 1.627×10^-27 kg

c= speed of light= 3×10^10cms-1

v= 1/2×3.142×3×10^10√240/1.627×10^-27

v= 5.3×10^-12 × 3.84×10^14

v= 20.4×10^2

v= 2040 cm-1

8 0

3 years ago

Enter the net ionic equation representing solid chromium (iii) hydroxide reacting with nitrous acid. express your answer as a ba

Colt1911 [192]

The net ionic equation of chromium (iii) hydroxide reacting with nitrous acid:

Cr(OH)₃ (s) + 3H⁺ (aq) ⇒ Cr³⁺ (aq) + 3H₂O (l)

<h3>Further explanation</h3>

The electrolyte in the solution produces ions.

The equation of a chemical reaction can be expressed in the equation of the ions

For strong electrolytes (the ionization rate = 1) is written in the form of separate ions, while the weak electrolyte (degree of ionization <1) is still written as an un-ionized molecule

In the ion equation, there is a spectator ion that is the ion which does not change (does not react) because it is present before and after the reaction

When these ions are removed, the ionic equation is called the net ionic equation

For gases and solids including water (H₂O) can be written as an ionized molecule

So only the dissolved compound is ionized ((expressed in symbol aq)

From the problem, it is stated that chromium (iii) hydroxide reacting with nitrous acid.

Reactions that occur:

Cr(OH)₃ (s) + 3HNO₂ (aq) ⇒ Cr(NO₂)₃ (aq) + 3H₂O (l)

Cr (OH)₃ solid form that does not decompose in the form of ions, as well as water (H₂O)

So the ionic equation becomes:

Cr(OH)₃ (s) + 3H⁺ (aq) + 3NO₂⁻ (aq) ⇒ Cr³⁺ (aq) + 3NO₂⁻ (aq) + 3H₂O (l)

There is an ion spectator that is 3NO₂⁻, so that if it is removed a net ionic equation will be formed:

Cr(OH)₃ (s) + 3H⁺ (aq) ⇒ Cr³⁺ (aq) + 3H₂O (l)

<h3>Learn more</h3>

the net ionic equation

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Keywords: the net ionic equation, an ion spectator

5 0

3 years ago

Read 2 more answers

A 100 gram glass container contains 200 grams of water and 50.0 grams of ice all at 0°c. a 200 gram piece of lead at 100°c is ad

ASHA 777 [7]

$0 \; \textdegree{\text{C}}$

Explanation:

Assuming that the final (equilibrium) temperature of the system is above the melting point of ice, such that all ice in the container melts in this process thus

$E(\text{fusion}) = m(\text{ice}) \cdot L_{f}(\text{water}) = 66.74 \; \text{kJ}$ and
$m(\text{water, final}) = m(\text{water, initial}) + m(\text{ice, initial}) = 0.250 \; \text{kg}$

Let the final temperature of the system be $t \; \textdegree{\text{C}}$ . Thus $\Delta T (\text{water}) = \Delta T (\text{beaker}) = t(\text{initial}) - t_{0} = t \; \textdegree{\text{C}}$

$Q(\text{water}) &= &c(\text{water}) \cdot m(\text{water, final}) \cdot \Delta T (\text{water})= 1.047 \cdot t\; \text{kJ}$ (converted to kilojoules)
$Q(\text{container}) &= &c(\text{glass}) \cdot m(\text{container}) \cdot \Delta T (\text{container})= 0.0837 \cdot t \; \text{kJ}$
$Q(\text{lead}) &= &c(\text{lead}) \cdot m(\text{lead}) \cdot \Delta T (\text{lead})= 0.0255 \cdot (100 - t)\; \text{kJ}$

The fact that energy within this system (assuming proper insulation) conserves allows for the construction of an equation about variable $t$ .

$E(\text{absorbed} ) = E(\text{released})$

$E(\text{absorbed} ) = E(\text{fushion}) + Q(\text{water}) + Q(\text{container})$
$E(\text{released}) = Q(\text{lead})$

Confirm the uniformity of units, equate the two expressions and solve for $t$ :

$66.74 + 1.047 \cdot t + 0.0837 \cdot t = 0.0255 \cdot (80 - t)$

$t \approx -55.95\; \textdegree{\text{C}} < 0\; \textdegree{\text{C}}$ which goes against the initial assumption. Implying that the final temperature does <em>not</em> go above the melting point of water- i.e., $t \le 0 \; \textdegree{\text{C}}$ . However, there's no way for the temperature of the system to go below $0 \; \textdegree{\text{C}}$ ; doing so would require the removal of heat from the system which isn't possible under the given circumstance; the ice-water mixture experiences an addition of heat as the hot block of lead was added to the system.

The temperature of the system therefore remains at $0 \; \textdegree{\text{C}}$ ; the only macroscopic change in this process is expected to be observed as a slight variation in the ratio between the mass of liquid water and that of the ice in this system.

3 0

3 years ago

Commercially available concentrated sulfuric acid is 17.2M . Calculate the volume of concentrated sulfuric acid required to prep

Dimas [21]

Answer:

0.727 l.

Explanation:

For the new dilute Sulphuric acid,

Number of moles = molar concentration × volume

= 2.5 × 5

= 12.5 mol

Volume of concentrated solution = 12.5/17.2

= 0.727 l of 17.2 M of sulphuric acid to be diluted.

5 0

3 years ago