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3 years ago

How many moles are in 20 grams of Ca (Calcium)? *

Chemistry

1 answer:

Flura [38]3 years ago

5 0

Answer:

0.49903 mol

Explanation:

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The difference in elevation between the highest and lowest contour lines on a topographical map is called:

Elena L [17]

I think the answer is D

7 0

3 years ago

Draw the bridged bromonium ion that is formed as an intermediate during the bromination of this alkene. Include hydrogen atoms,

vivado [14]

Answer:

See explanation and image attached

Explanation:

The reaction of bromine molecule with an alkene passes through a bridged intermediate known as the brominium ion.

It is a cyclic intermediate that contains a positively charged bromine ion as i have shown in the image attached.

The brominium ion is first formed during the bromininaton of alkenes.

4 0

3 years ago

14. A piece of titanium at 100.0°C was dropped into 50.0 g of water at 20.0°C. The final temperature of the system was 22.6°C. W

Gemiola [76]

Answer:

$m_{Ti}=13.0g$

Explanation:

Hello,

In this case, based on the given, we can infer that as titanium is hot and water cold, it cools down whereas the water is heated up, therefore, in terms of heat, we have that the heat lost by the titanium is gained by the water:

$-Q_{Ti}=Q_{H_2O}$

That in terms of mass, specific heat and temperatures is:

$-m_{Ti}Cp_{Ti}(T_2-T_{Ti})=m_{H_2O}Cp_{H_2O}(T_2-T_{H_2O})$

In such a way, for computing the mass of titanium, considering the heat capacity of water 4.18 J/g°C, we have:

$m_{Ti}=\frac{m_{H_2O}Cp_{H_2O}(T_2-T_{H_2O})}{-Cp_{Ti}(T_2-T_{Ti})} \\\\m_{Ti}=\frac{50.0g*4.18\frac{J}{g\°C}(22.6-20.0)\°C}{-0.54\frac{J}{g\°C}*(22.6-100.0)\°C} \\\\m_{Ti}=13.0g$

Regards.

8 0

3 years ago

Help! 100 point and I will give a brainliest and 5 star for solving this question.

inn [45]

Mass of H_2SO_4 required

Molarity

Moles of solute/Volume of solution in L

0.1=n/0.1L
n=0.1(0.1)
n=0.01mol

Now molar mass of H_2SO_4

2(1)+32+4(16)
2+32+64
98g/mol

Mass

98(0.01)
0.98g

7 0

2 years ago

How many atoms are in a sample of 175 g of sodium (Na)?

denis-greek [22]

Stoichiometry!
You'll have to take the 175g of Na and convert it to moles if you want to turn this amount into atoms. Thus, you will have to divide 175g by the molar mass of Na that can be found on the periodic table, which can be rounded to 22.99g. That should give you 7.61 mols. However, since the question is asking for atoms, you'll have to bring in Avogadro's number of 6.022*10^23.
So by taking the 7.61 mols, you'll have to multiply that by 6.022*10^23 in order to get 4.58*10^24 atoms which is B.

A simplified version of all that ^ is:
175g (6.022*10^23) / 22.99g = 4.58*10^24.

5 0

3 years ago