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2 years ago

The glass hand bubbler holds a red liquid. When it heats up, do you see a chemical change or a physical change? How do you know?

Chemistry

1 answer:

Crank2 years ago

7 0

Answer:

Chemical change

Explanation:

Bubbles are usually a sign of a chemical reaction in the form of a gas so I would say this is a chemical change

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PLZ HELP IM GIVING BRAINLEST TO WHOEVER HELPS ME AND GETS THE RIGHT ANSWER.

Nana76 [90]

Answer:

From hot tea to the ice cube

From the warm coffee to my cold hands

From the hot sand to my feet

Explanation:

Heat always travels from a hot object to a colder object, until equilibrium is reached and the objects are at the same temperature.

5 0

3 years ago

Read 2 more answers

A student isolated 7.2 g of 1-bromobutane reacting equimolar amounts of 1-butanol (10 ml) and NaBr (11.1 g) in the presence of s

Alla [95]

Answer: The percent yield of the 1-bromobutane is 48.65 %

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

For NaBr:

Given mass of NaBr = 11.1 g

Molar mass of NaBr = 103 g/mol

Putting values in equation 1, we get:

$\text{Moles of NaBr}=\frac{11.1g}{103g/mol}=0.108mol$

The chemical equation for the reaction of 1-butanol and NaBr is:

$\text{1-butanol + NaBr}\rightarrow \text{1-bromobutane}$

By Stoichiometry of the reaction

1 mole of NaBr produces 1 mole of 1-bromobutane

So, 0.108 moles of NaBr will produce = $\frac{1}{1}\times 0.108=0.108$ moles of 1-bromobutane

Now, calculating the mass of 1-bromobutane from equation 1, we get:

Molar mass of 1-bromobutane = 137 g/mol

Moles of 1-bromobutane = 0.108 moles

Putting values in equation 1, we get:

$0.108mol=\frac{\text{Mass of 1-bromobutane}}{137g/mol}\\\\\text{Mass of 1-bromobutane}=(0.108mol\times 137g/mol)=14.80g$

To calculate the percentage yield of 1-bromobutane, we use the equation:

$\%\text{ yield}=\frac{\text{Experimental yield}}{\text{Theoretical yield}}\times 100$

Experimental yield of 1-bromobutane = 7.2 g

Theoretical yield of 1-bromobutane = 14.80 g

Putting values in above equation, we get:

$\%\text{ yield of 1-bromobutane}=\frac{7.2g}{14.80g}\times 100\\\\\% \text{yield of 1-bromobutane}=48.65\%$

Hence, the percent yield of the 1-bromobutane is 48.65 %

5 0

2 years ago

Correct forms of the equation of Charles’s law is (are)

xxTIMURxx [149]

According to Charles' Law the volume of an ideal gas is directly proportional to its absolute temperature in Kelvin keeping the pressure constant.

V∝ T, P is constant

where V, T and P are volume, temperature and pressure

$\frac{V1}{T1 }$ = $\frac{V2}{T2}$

where V₁, T₁, V₂ and T₂ are initial volume, initial temperature, final volume and final temperature.

8 0

3 years ago

Explain why energy sources do not have 100% efficiency. Why do you think some have lower efficiencies?

bearhunter [10]

Answer:

Energy sources do not have 100% efficiency because the processes of energy conversion to usable forms involves energy losses.

Some have lower efficiencies due to; energy losses in form of heat during conversion, poor technology applied during conversion of energy and lack of desire equipment to use in the energy conversion system.

Explanation:

The desired form of energy for use is derived from conversion of energy from the source using an energy converter into another form which is usable. The efficiency of the energy converter is calculated as;

л = output energy/input energy

The efficiency of energy is limited to the cost of equipment required for conversion from energy source by the energy converter to a form which is usable. Additionally, because energy sources are scarce, the technology to use in energy conversion is a factor affecting energy efficiency in that high efficiency will require advanced technology with better equipment leading higher costs of that energy form. when heat losses are involved during energy conversion, efficiency lowers, thus its better if such losses are used as energy input in another system.

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2 years ago

How does nuclear fission of Uranium - 234 result in electricity being generated?

nevsk [136]

Answer:

See explanation

Explanation:

The use of Uranium - 234 to generate electricity depends on a fission reaction. The uranium nuclide is bombarded by fast moving neutrons leading to a chain reaction. Control rods and moderators are used to keep the nuclear reaction under control.

As the nuclear reaction proceeds, heat is generated and steam is consequently produced. This steam is used to turn a turbine and electricity is thereby generated.

7 0

2 years ago