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What does pressure measure

omeli [17]

Answer:

C

Explanation:

Pressure it says it in the name its the force of colliding particles

6 0

4 years ago

Using the following thermochemical data: 2Y(s) + 6HF(g) → 2YF3(s) + 3H2(g) ΔH° = –1811.0 kJ/mol 2Y(s) + 6HCl(g) → 2YCl3(s) + 3H2

Luba_88 [7]

Answer:

ΔH° = 182.4 kJ/mol

Explanation:

The ΔH wanted is for the reaction :

YF3(s) + 3HCl(g) → YCl3(s) + 3HF(g)

This is a Hess Law problem where e will have to algebraically manipulate the first and second equations , add them together, and arrive at the desired equation above.

Notice if we reverse the first equation and divide it by 2 and add to the the second only divided by two, we will arrive to the desired equation:

2YF3(s) + 3H2(g) → 2Y(s) + 6HF(g) ΔH° = 1811.0 kJ/mol (change sign)

dividing by two :

YF3(s) + 3/2H2(g) → Y(s) + 3HF(g) ΔH° = 905.5 kJ/mol Eq 1

2Y(s) + 6HCl(g) → 2YCl3(s) + 3H2(g) ΔH° = –1446.2 kJ/mol

dividing this one by two,

Y(s) + 3HCl(g) → YCl3(s) + 3/2 H2(g) ΔH° = –1446.2 kJ/mol/2 = - 723.10 kJ/mol Eq 2

Now adding 1 and 2

YF3(s) + 3/2H2(g) → Y(s) + 3HF(g) ΔH° = 905.5 kJ/mol Eq 1

Y(s) + 3HCl(g) → YCl3(s) + 3/2 H2(g) ΔH° = –1446.2 kJ/mol/2 = - 723.10 kJ/mol Eq 2

________________________________________________________

YF3(s) + 3HCl(g) → YCl3(s) + 3HF(g). ΔH° = 905.5 + (-723.1) kJ/mol

ΔH° = 182.4 kJ/mol

Notice how the Y(s) and H2 cancel nicely and the coefficients are the right ones.

8 0

4 years ago

A woman with diagnosed osteoporosis is told by her doctor to take 1,000 mg of calcium carbonate in addition to increasing intake

spayn [35]

Answer:

400 mg

Explanation:

Given:

A woman with is told by her doctor to take 1,000 mg of calcium carbonate.

Question asked:

How many mg of calcium are in this 1,000 mg regimen of calcium carbonate?

Solution:

As we know:

<em>Amount of elemental calcium in a medicine containing calcium carbonate = 40%</em>

As here doctor prescribed 1000 mg of calcium carbonate to be taken by the woman increasing intake of calcium-containing foods in her diet and including regular weight-bearing exercise, hence amount of elemental calcium in 1,000 mg regimen of calcium carbonate will be,

$40\%\ of\ 1000\ mg\\\frac{40}{100} \times1000\ mg\\\frac{40000}{100} = 400\ mg$

Therefore, 400 mg of calcium are in this 1,000 mg regimen of calcium carbonate.

6 0

4 years ago

How do I find the rate of reaction on a graph

Nonamiya [84]

Rate of reaction can be understood as the rate of change of the materials, such as the rate of depletion of the reactants or the rate of production of products. Therefore, if a graph of concentration and time is plotted, the rate of reaction is simply the slope of the graph.

3 0

3 years ago

Is phosphorous an atom, element, or compound

Marrrta [24]

Answer:

its element

Explanation:

7 0

3 years ago

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