Answer:
It depends on what kine of unknown substance you're referring to.
Explanation:
What do you mean by unknown substance?
If it's soluble in water and can conduct electricity then it is an ionic compound.. If it is insoluble in water and can't conduct electricity then it is a covalent compound
<span>This question is simple, answers are D and C respectively</span>
Answer:
The answers are
1. Scientists use seismometers to measure the earthquake activity that occurs beneath a volcano. They then predict the eruption of that volcano.
2. Scientists measure the amount of these gases to determine the amount of magma present in the volcanic reservoir.
Explanation:
When a volcano is near eruption Earthquake activity gets stronger and stronger. Scientists use a wide variety of techniques to monitor volcanoes, including seismographic detection of the earthquakes and tremor that almost always precede eruptions, precise measurements of ground deformation that often accompanies the rise of magma, changes in volcanic gas emissions, and changes in gravity and.
Scientists can use the FTIR or Fourier Transform Infrared Spectrometer to measure dissolved volatile concentrations as described above or can be used to measure several gases emitted from a volcano simultaneously. The device can be used both as an open-path or closed-path system. I had just taken the test and got the question right as well
You need to use the Ka for the acetic acid and the equilibrium equation.
Ka = 1.85 * 10^ -5
Equilibrium reaction: CH3COOH (aq) ---> CH3COO(-) + H(+)
Ka = [CH3COO-][H+] / [CH3COOH]
Molar concentrations at equilibrium
CH3COOH CH3COO- H+
0.50 - x x x
Ka = x*x / (0.50 - x) = x^2 / (0.50 - x)
Given that Ka is << 1 => 0.50 >> x and 0.50 - x ≈ 0.50
=> Ka ≈ x^2 / 0.50
=> x^2 ≈ 0.50 * Ka = 0.50 * 1.85 * 10^ -5 = 0.925 * 10^ - 5 = 9.25 * 10 ^ - 6
=> x = √ [9.25 * 10^ -6] = 3.04 * 10^ -3 ≈ 0.0030
pH = - log [H+] = - log (x) = - log (0.0030) = 2.5
Answer: 2.5
The the strength of an electromagnet varies with the quantity and direction of current as well as the number of turns in the coil.
<h3>What as is an electromagnet?</h3>
An electromagnet is a material which operates by the principle of electromagnetism.
Electromagnets possesses both electrical and magnetic properties.
The strength of an electromagnet is affected by the current, the number of turns as well as the material of the electromagnet.
The strength of the given electromagnet will be affected thus:
- increases when using a battery with a higher voltage
- decreases when wrapping the wire around the nail only three times
- is unchanged when changing the direction of the current by reversing the battery connections
- decreases when using a plastic stick in place of the iron nail
- is greatest when holding the nail vertically rather than horizontally.
Therefore, the strength of an electromagnet is affected by current and number of turns in the coil.
Learn more about electromagnets at: brainly.com/question/12555869
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