Which of the following changes

Can some one help me in this I hope this will be easy for you :)

kramer

Answer:

c) i) Mg²⁺ ii) O²⁻

Explanation:

I don't know the answer to Q7. because you don't show the diagram

5 0

3 years ago

At sea level water usually boils at 100. °C and 760. mmHg pressure. On Mt Whitney, the pressure is about 560. mmHg. At what temp

WITCHER [35]

Answer:

91.7°C

Explanation:

We suppose you have a formula to work from. However, that is not supplied with this problem statement, so we looked one up.

The formula in the attachment is supposed to have good accuracy in the temperature range of interest. It gives vapor pressure of water in kPa, not mmHg, so we needed the conversion for that, too.

560 mmHg corresponds to about 74.66 kPa. The attached "Buck equation" formula is used to find the corresponding temperature. The exponential equation could be solved algebraically using logarithms and the quadratic formula, but we choose to find the solution graphically.

Water boils at about 91.7 °C on Mt. Whitney.

7 0

3 years ago

How many grams of nan3 are required to produce 19.0 ft3 of nitrogen gas, about the size of an automotive air bag, if the gas has

Papessa [141]

The balanced chemical reaction is given as:

$2NaN_{3}(s)\rightarrow 2Na(s)+3N_{2}(g)$

Now, convert $19.0 ft^{3}$ into litres.

$1 ft^{3} = 28.3168$

So, $19.0 ft^{3} = 19\times 28.3168 = 538.0192 L$

Density is equal to the ratio of mass to the volume.

$D=\frac{M}{V}$

where, M = mass and V= volume $(538.0192 L)$

Substitute the value of density and volume in formula to get the value of mass.

$1.25 g/L=\frac{M}{538.0192 L}$

$1.25 g/L\times 538.0192 L= M$

$Mass = 672.524 g$

Now, number of moles of $N_{2}$ gas= $\frac{672.524 g}{28.02 g/mol}$

= $24.00 moles$

According to the reaction, 2 moles of sodium azide gives 3 moles of nitrogen gas.

Now, in 24.00 moles of nitrogen gas produced from= $\frac{2 moles of sodium azide}{3 moles of nitrogen gas}\times 24.00 moles$ of nitrogen gas, moles of sodium azide.

number of moles of sodium azide = $16 moles$

Mass of sodium azide in g = $number of moles\times molar mass of sodium azide$ .

= $16 moles\times 65.00 g/mol$

= $1040 g$

Thus, mass of sodium azide which is required to produce $19.0 ft^{3}$ of nitrogen gas = $1040 g$

3 0

3 years ago

Hydrogen, a potential future fuel, can be produced from carbon (from coal) and steam by the following reaction: C(s)+2H2O(g)→2H2

madam [21]

The question is incomplete , complete question is:

Hydrogen, a potential future fuel, can be produced from carbon (from coal) and steam by the following reaction:

$C(s)+ 2 H_2O(g)\rightarrow 2H_2(g)+CO_2(g).\Delta H=?$

Note that the average bond energy for the breaking of a bond in CO2 is 799 kJ/mol. Use average bond energies to calculate ΔH of reaction for this reaction.

Answer:

The ΔH of the reaction is -626 kJ/mol.

Explanation:

$C(s)+ 2 H_2O(g)\rightarrow 2H_2(g)+CO_2(g).\Delta H=?$

We are given with:

$\Delta H_{H-O}=459 kJ/mol$