All categories

3 years ago

Which sample of matter has a crystal structure?

1 answer:

3 0

A crystalline structure is any structure of ions, molecules, or atoms that are held together in an ordered, three-dimensional arrangement. It is composed of a unit cell, a set of atoms arranged in a particular way; which is periodically repeated in three dimensions on a lattice.

You might be interested in

On a day wilderness expedition you'll need to heat of water to the boiling point each day. The air temperature will average . Yo

AlladinOne [14]

Answer:

Your question is not complere. but maybe it is like:

5 day expedition.

you'll need to heat 4.0kg

Air Temperature: 25 °C

each canister has 75 g

The standar heat of formation of propane at 25°C is −103.85 / kJmol...

If the data is not exactly the same, you can follow the same steps.

Explanation:

Given:

Weight of water = 4.0 kg = 4000 g

Boiling point = 100 °C (T2)

Initial T ° Water= 25 °C (T1)

Specific heat capacity water (Cs) = 4.184 J / g°C

Then

Energy (q) = m x Cs x (T2-T1)

q = 4000 g x 4.184 J / g°C x (100-25) °C

q = 1255200 J per day

For 5 days the amount of energy will be 5xq = 6276000 J = 6276 kJ

Then we know that the standard heat of formation of propane at 25°C is −103.85kJ/mol. Also, Molecular Weight propane= 44,1 g / mol

Then we can know how much propane it's needed:

Mass= 6276 kJ÷103.85 kJ / mol = 60.43 mol

Mass of propane= 60.43 mol × 44,1 g/mol = 2664.9 g

So, if each canister has 75.g of propane:

Number of canister= 2664.9 g ÷ 75.g = 35.53 = 36 canisters

4 0

3 years ago

Read 2 more answers

Considering the following precipitation reaction: Pb(NO3)2(aq) + 2KI(aq) → PbI2(s) + 2KNO3(aq),

patriot [66]

Answer: The ions which are not spectator ions are $Pb^{2+}$ and $I^-$

Explanation:

Spectator ions are defined as the ions which does not get involved in a chemical equation or they are ions which are found on both the sides of the chemical reaction present in ionic form.

The given chemical equation is:

$Pb^{2+}(aq)+NO_3^-(aq)+2K^+(aq)+2I^-(aq)\rightarrow PbI_2(s)+2K^+(aq)+2NO_3^-(aq)$

The ions which are present on both the sides of the equation are $K^+$ and $NO_3^-$ and are spectator ions.

Thus the net ionic equation is:

$Pb^{2+}(aq)+2I^-(aq)\rightarrow PbI_2(s)$

Hence, the correct answer is $Pb^{2+}$ and $I^-$

5 0

3 years ago

Read 2 more answers

What determines what elements end up on the periodic table?

AfilCa [17]

Their atomic number

7 0

3 years ago

Alkanes do not have geometric isomers because the carbon atoms in their carbon-carbon bonds are _____.

Mariana [72]

The word that best fits the underlined in the sentence is "free-to-rotate." The carbon atoms in their carbon bonds are free to rotate since alkanes do not have geometric isomers. They only have single bonds and the most common example of which are trans molecules.

6 0

3 years ago

Read 2 more answers

13) Find the mass, in grams, of 5.75 liters of N2.

faltersainse [42]

Molecular weight of N2
gram Atomic weight of N is 14 g.
gram Molecular weight = 14 g×2
= 28 g
Liter concepts
1 liter of gas always occupies 1 gram molecular weight .
Application of the concept
5.75 liter gives 0.257g

1 mole will occupy 28 g

0.257 will occupy 28 g × 0.257
= 7.196 g

The mass of the gas is 7.196 g.

Hope it helps you

8 0

3 years ago