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3 years ago

If 11.9 kJ are used to heat a sample of water the temperature increases from 20.0°C to

Chemistry

1 answer:

Kipish [7]3 years ago

7 0

Answer:

$m=4.51g$

Explanation:

Hello!

In this case, since the energy involved during a heating process is shown below:

$Q=mCp\Delta T$

Whereas the specific heat of water is 4.184 J/(g°C), we can compute the heated mass of water by the addition of 11.9 kJ (11900 J) of heat as shown below:

$m=\frac{Q}{Cp\Delta T}$

Thus, by plugging in, we obtain:

$m=\frac{11900J}{4.184\frac{J}{g\°C}(650\°C-20.0\°C)}\\\\m=4.51g$

Best regards!

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Los isomeros ópticos

krek1111 [17]

Answer:

Los isómeros ópticos son dos compuestos que contienen el mismo número y tipo de átomos, y enlaces (es decir, la conectividad entre los átomos es la misma), y diferentes disposiciones espaciales de los átomos, pero que tienen imágenes especulares no superponibles. Cada estructura de imagen especular no superponible se denomina enantiómero.

Explanation

7 0

3 years ago

Convert 632 mmHg to kPa

Ilia_Sergeevich [38]

Answer:
84.259 kPa

Explanation:
We know that:
1 kPa is approximately equal to 7.5 mmHg
Therefore, to convert 632 mmHg to kPa, we will simply use cross multiplication as follows:
1 kPa .................> 7.5006 mmHg
?? kPa ................> 632 mmHg
632 mmHg = (632*1) / (7.5006) = 84.259 kPa

Hope this helps :)

3 0

4 years ago

Read 2 more answers

Consider the reaction Mg₂Si(s) + 4 H₂O(ℓ) → 2 Mg(OH)₂(aq) + SiH₄(g). How many grams of silane gas (SiH₄) are formed if 25.0 g of

Neko [114]

Answer:

10.60 grams of silane gas are formed.

Explanation:

From the reaction:

Mg₂Si(s) + 4H₂O(l) → 2Mg(OH)₂(aq) + SiH₄(g)

We know that the limiting reactant is Mg₂Si, so to find the mass of SiH₄ formed we need to calculate the number of moles of Mg₂Si:

$\eta_{Mg_{2}Si} = \frac{m_{Mg_{2}Si}}{M_{Mg_{2}Si}}$

Where:

m: is the mass of Mg₂Si = 25.0 g

M: is the molar mass of Mg₂Si = 76.69 g/mol

$\eta_{Mg_{2}Si} = \frac{m_{Mg_{2}Si}}{M_{Mg_{2}Si}} = \frac{25.0 g}{76.69 g/mol} = 0.33 moles$

Now, the stoichiometric relation between Mg₂Si and SiH₄ is 1:1 so:

$\eta_{Mg_{2}Si} = \eta_{SiH_{4}} = 0.33 moles$

Finally, the mass of SiH₄ is:

$m_{SiH_{4}} = \eta_{SiH_{4}}*M_{SiH_{4}} = 0.33 moles*32.12 g/mol = 10.60 g$

Therefore, 10.60 grams of silane gas are formed.

I hope it helps you!

3 0

3 years ago

What is the empirical formula of a compound consisting of 29.6% oxygen and 70.4% fluorine by mass?

Rainbow [258]

O1Fl2

1. Assume an 100g sample, so the percentage will stay the same

2. Covert each element into their molar mass
29.6/16.00=1.8 mols of O
70.4/19.00=3.7 mols of Fl

3. Divide both by the smallest value of mol
1.8/1.8=1 O
3.7/1.8=2 Fl

4. Write the empirical formula:
O1Fl2

3 0

3 years ago

Read 2 more answers

Calculate the density of the four solutions. All of the solutions has the volume equal to 25 ml. Red solution has 25.0 g of mass

Scilla [17]

Answer:

B. Green solution density is 1.06 g/ml and blue solution density is 1.20 g/ml

Explanation:

Density is given as,

D = Mass / Volume

Red Solution,

D = 25 g / 25 mL

D = 1 g/mL

Green Solution,

D = 26.5 g / 25 mL

D = 1.06 g/mL

Yellow Solution,

D = 28.2 g / 25 mL

D = 1.128 g/mL

Blue Solution,

D = 30 g / 25 mL

D = 1.20 g/mL

3 0

3 years ago