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2 years ago

Mrs. Jacobson is pushing a fridge to the right with a force of 100 N. The force pushing it

Chemistry

2 answers:

alex41 [277]2 years ago

8 0

Answer:

Explanation:

Let's illustrate this; see the attachment.

We see that Mrs. Jacobson is pushing to the right with a force of 100 N and there is another opposite force pushing with a force of 15 N. Since these are in opposite directions, we can say that the force opposite to Mrs. Jacobson is pushing the fridge -15 N to the right (instead of 15 N to the left).

The net force would then be:

100 N + (-15 N) = 85 N to the right

The answer is A.

Nataly_w [17]2 years ago

7 0

Answer:

85 N to the right

Explanation:

Convention: rightwards positive

Force applied by Mrs. Jacobson:

+100

Force applied by the fridge:

-15

Net force

+100 - 15

+85

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A Mole of elephants would weigh how much more than the moon? I got 6.301x10^23 and set the problem up like this: 6.022x10^23 x 2

Margaret [11]

Answer:

The Moon weighs about 7.349*10^22 kg

How much does “an elephant” weigh? Grown-up elephants vary between 1.7 tons (small wood elephant cow) and 6 tons (big African elephant bull). Let us pick 2.720 tons or 2720 kg as an average weigh one, this is valid for Asian elephants.

A mole of elephants weighs 6.022 * 10^23 x 2720 kg = 1.638 * 10^27 kg.

That is 1,638 * 10^27 / 7,349*10^22 = 22289 times more.

5 0

2 years ago

A precipitate of zinc hydroxide can be formed using the reaction below.

worty [1.4K]

Answer:

Option B is correct. KOH is the limiting reagent, and 0.27 mole of Zn(OH)2 precipitate is produced.

Explanation:

Step 1: Data given

Number of moles ZnCl2 = 0.36 moles

Number of moles KOH = 0.54 moles

Step 2: The balanced equations

ZnCl2(aq) + 2 KOH(aq) → Zn(OH)2(s) + 2 KCl(aq)

For 1 mol ZnCl2 we need 2 moles KOH to produce 1 mol Zn(OH)2 and 2 moles KCl

Step 3: Calculate the limiting reactant.

KOH is the limiting reactant. It will completely be consumed (0.54 moles). ZnCl2 is in excess. There will react 0.54/2 = 0.27 moles

There will remain 0.36 - 0.27 = 0.09 moles.

Step 4: The products

There will be produced 2 moles KCl and 1 mol Zn(OH)2. Zn(OH)2 is the precipitate produced.

For 1 mol ZnCl2 we need 2 moles KOH to produce 1 mol Zn(OH)2 and 2 moles KCl

For 0.54 moles KOH, we will produce 0.27 moles precipitate (Zn(OH)2)

Option A is not correct because 0.27 mol of Zn(OH)2 will precipitate, not 0.54 mol

Option B is correct

Option C is not correct because ZnCl2 is not the limiting reactant, but the excess reactant

Option D is not correct because ZnCl2 is not the limiting reactant, but the excess reactant

7 0

2 years ago

How many moles of koh are contained in 750. ml of 5.00 m koh solution?

Marat540 [252]

Molarity is one of the method of expressing concentration of solution. Mathematically it is expressed as,
Molarity = $\frac{\text{number of moles of solute}}{\text{volume of solution (l)}}$

Given: Molarity of solution = 5.00 M
Volume of solution = 750 ml = 0.750 l

∴ 5 = $\frac{\text{number of moles}}{.750}$
∴ number of moles = 3.75

Answer: Number of moles of KOH present in solution is 3.75.

4 0

2 years ago

In the equilibrium system described by: PO43-(aq) + H2O(1) = HPO42-(aq) + OH-(aq) Brønsted-Lowry theory would designate: A) PO43

Kamila [148]

Answer:

The correct option is: B) H₂0 and OH⁻ as a conjugate pair

Explanation:

According to Brønsted-Lowry theory, the acids are the chemical substances that form a conjugate base by donating a proton and bases are the chemical substances that form conjugate acid by accepting a proton.

In the given chemical reaction: PO₄³⁻(aq) + H₂O(l) ⇄ HPO₄²⁻(aq) + OH⁻(aq)

According to Brønsted-Lowry theory, PO₄³⁻ and OH⁻ are bases. Whereas, H₂O and HPO₄²⁻ are acids.

Also, PO₄³⁻ and HPO₄²⁻ are the conjugate acid-base pair; and H₂O and OH⁻ are the conjugate acid-base pair.

6 0

2 years ago

Why the gross reading is needed when doing the titration?

aleksklad [387]

Answer:

The answer is below

Explanation:

Because various factors can affect the actual value of the titration outcome. Some of these factors can range from errors from a researcher also known as human error, misreading the quantities, researcher's perception of the color, or wrong procedure in carrying out the experimentation.

Hence, in order to avoid such error, a researcher needs to be thorough during the process of experimentation, and using gross reading can help to avoid these errors when the titre value is eventually determined.

7 0

2 years ago