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3 years ago

Which statement about electric and magnetic fields is true.

2 answers:

5 0

The correct answer is 2. Magnetic fields must start at the north pole of a magnet and end at the south pole of a magnet. I took the test. Hope I helped!

11Alexandr11 [23.1K]3 years ago

4 0

Answer:

Magnetic fields must start at the north pole of a magnet and end at the south pole of the magnet.

Explanation:

The lines that shows the direction of electric and magnetic field are called electric and magnetic field lines.The direction of electric field is from positive charge to negative charge.

The magnetic filed lines start at the north pole of a magnet and end at the south pole of the magnet.

Hence, the correct option is (2) "Magnetic fields must start at the north pole of a magnet and end at the south pole of the magnet".

You might be interested in

How many atoms of carbon are in a pencil if the mass of carbon is 2.00 g.?

yulyashka [42]

so, There are (1/12.0)moles with each mole having 6.022 x10^23 atoms. 1 mole of carbon-12 has 6.02 x 1023 iotas.

3 0

3 years ago

A solution has a volume of 375 ml and contains 12.6 moles of NaCI what is it molarity

miskamm [114]

Answer:

M = 33.6M .

Explanation:

Hello there!

In this case, according to the definition of molarity which is computed by dividing the moles of solute by the liters of solution, it is possible to realize that the moles of the solute are 12.6 mol and the liters of solution are 375/1000= 0.375 L and therefore the molarity of the solution can be calculated as follows:

$M=\frac{12.6mol}{0.375L}\\\\M=33.6M$

Which has molar units, M.

Regards!

4 0

3 years ago

A Cu2+ solution is prepared by dissolving a 0.4749 g piece of copper wire in acid. The solution is then passed through a Walden

Luda [366]

Answer:

Concentration of $Cr_2O_7^{2-}$ = 0.03101 M

Concentration of $MnO_4^-$ = 0.03721 M

Explanation:

The reduction for $Cr_2O_7^{2-}$ is;

$Cr_2O_7^{2-} + 14 H ^+ _{(aq)} + 6 e^- -----> 2 Cr^{3+} _{(aq)}+7H_2O _{(l)}$

$Cu^+_{(aq)} -----> Cu^{2+} _{(aq)} + 1 e^-$

6 moles of $Cu ^+$ = 1 mole of $Cr_2O_7^{2-}$

number of moles of Cu reacted = $\frac{mass \ of \ Cu \ wire }{ molecular weigh tof \ Cu wire }$

number of moles of Cu reacted = $\frac{0.4749}{63.55}$

number of moles of Cu reacted = 0.00747 mole

number of moles of $Cr_2O_7^{2-}$ reacted = $\frac{0.00747}{6}$

number of moles of $Cr_2O_7^{2-}$ reacted = 0.001245 mole

Concentration of $Cr_2O_7^{2-}$ = $\frac{number \ of moles }{Volume}$

Given that the volume = 40.15 mL = $40.15 *10^{-3}$ ; we have:

Concentration of $Cr_2O_7^{2-}$ = $\frac{0.001245}{40.15*10^{-3}}$

Concentration of $Cr_2O_7^{2-}$ = 0.03101 M

The reduction for $MnO_4^-$ is;

$MnO_4^- + 8H^+ + 5 e^- -----> Mn^{2+} + 4H_2O$

$Cu^+_{(aq)} -----> Cu^{2+} _{(aq)} + 1 e^-$

5 moles of $Cu ^+$ = 1 mole of $Cr_2O_7^{2-}$

number of moles of Cu reacted = $\frac{mass \ of \ Cu \ wire }{ molecular weigh tof \ Cu wire }$

number of moles of Cu reacted = $\frac{0.4749}{63.55}$

number of moles of Cu reacted = 0.00747 mole

number of moles of $MnO_4^-$ reacted = $\frac{0.00747}{5}$

number of moles of $MnO_4^-$ reacted = 0.001494 mole

Concentration of $MnO_4^-$ = $\frac{number \ of moles }{Volume}$

Given that the volume = 40.15 mL = $40.15 *10^{-3}$ ; we have:

Concentration of $MnO_4^-$ = $\frac{0.001494 }{40.15*10^{-3}}$

Concentration of $MnO_4^-$ = 0.03721 M

3 0

4 years ago

What is the titration

Inga [223]

Titration is the slow edition of one solution of unknown concentration to a noun volume up another solution of unknown concentration until the reaction reaches neutralization which is often indicated by a color change

7 0

3 years ago

Convert the following measurements using dimensional analysis. Set up problem using factors. Cross out the units that cancel. YO

uranmaximum [27]

Answer:

1) 0.423 m

2) 3.107 mi

3) 68.18 kg

4) 0.0083 mem

5) 0.528 gal

6) 4300 mL

7) 32.4 mem

8) 523.013 km

9) 70.866 in

10) 2.3 yek

Note: I can’t type the about equal to sign or the sign that shows a repeating decimal, so check the image for that and my work.

Explanation:

4 0

3 years ago