Which liquid would be the most difficult to raise or lower the temperature of

When 35.0 mL of 0.400 M hydrobromic acid and 35.0 mL of 0.400 M ammonia are combined, the pH of the resulting solution will be :

Kay [80]

Answer:

B. Equal to 7.

Explanation:

Hydrobromic acid is a strong acid that decreases pH and ammonia is a strong base that increases pH.

As the initial pH of water is 7,0 the addition of 35.0mL of 0.400M HBr will produce a pH less than 7,0. But, the same effect of decreasing pH is reverted for the addition of 35.0mL of 0.400M HNO3.

That means the net effect of the two addition is to have a pH:

B. Equal to 7.

I hope it helps!

3 0

3 years ago

A 30.7 g sample of Strontium nitrate, Sr(NO3)2•nH2O, is heated to a constant mass of 22.9 g. Calculate the hydration number.

Elodia [21]

Answer:

Hydration number: 4

Explanation:

1) Mass of water in the hydrated compound

Mass of water = Mass of the hydrated sample - mass of the dehydrated compound

Mass of water = 30.7 g - 22.9 g = 7.8 g

2) Number of moles of water

Number of moles = mass in grams / molar mass

molar mass of H₂O = 2×1.008 g/mol + 15.999 g*mol = 18.015 g/mol

Number of moles of H₂O = 7.9 g / 18.015 g/mol = 0.439 mol

3) Number of moles of Strontium nitrate dehydrated, Sr (NO₃)₂

The mass of strontium nitrate dehydrated is the constant mass obtained after heating = 22.9 g

Molar mass of Sr (NO₃)₂ : 211.63 g/mol (you can obtain it from a internet or calculate using the atomic masses of each element from a periodic table).

Number of moles of Sr (NO₃)₂ = 22.9 g / 211.63 g/mol = 0.108 mol

4) Ratio

0.439 mol H₂O / 0.108 mol Sr(NO₃)₂ ≈ 4 mol H₂O : 1 mol Sr (NO₃)₂

Which means that the hydration number is 4.

4 0

4 years ago

Read 2 more answers

The isomerization of methylisonitrile to acetonitrileCH3NC(g)→CH3CN(g)is first order in CH3NC . The rate constant for the reacti

lisabon 2012 [21]

Answer:

Option E, Half life = $2.96\times 10^3\ s$

Explanation:

For a first order reaction, rate constant and half-life is related as:

$t_{1/2}=\frac{0.693}{k}$

Where,

$t_{1/2}$ = Half life

k = Rate constant

Rate constant given = $2.34\times 10^{-4}\ s^{-1}$

$t_{1/2}=\frac{0.693}{k}$

$=\frac{0.693}{2.34 \times 10^{-4}}=2.96\times 10^3\ s$

So, the correct option is option E.

4 0

4 years ago

Why do planets in our solar system stay in their positions

Anon25 [30]

This is not chemistry but it's A, off top.

4 0

4 years ago

Read 2 more answers

In the essay box, compose a scientific report which includes your observations, data, and conclusions. The following questions s

timama [110]

Answer:

1. It depends what type of method you are using. if it is Height x Width x Length then it will not work for an irregular shape because it has extra pieces that would not be included.

2. The second method would work for both regular and irregular shapes because you would have to know or find out the volume of the regular shape to get the volume for the irregular shape.

3. It also depends on what you are doing, if you are doing a regular shape then use the first method, if it's an irregular shape then use the second method, if you do the maths correctly both should give you an accurate answer for what you want to achieve.

4. No, because the sugar would dissolve.

5. No, on this case the displacement method would not work because of the weight difference

Explanation:

All the answers for you!

4 0

3 years ago