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sasho [114]
2 years ago
7

Polycarbonate plastic has a density of 1.2 g/cm3 . A photo frame is constructed from two 3.0 mm sheets of polycarbonate. Each sh

eet measures 28 cm by 22 cm. What is the mass of the photo frame?
Chemistry
1 answer:
valina [46]2 years ago
6 0
<span>440 g First, determine the volume of each sheet. And it's easier if each dimension is using the same unit of measure. So each sheet is 28 cm by 22 cm by 0.30 cm. Multiply them together 28 cm * 22 cm * 0.30 cm= 184.8 cm^3 Since we have 2 identical sheets, double the total volume 184.8 cm^3 * 2 = 369.6 cm^3 Now multiple the volume by the density 369.6 cm^3 * 1.2 g/cm^3 = 443.52 g Round the results to 2 significant digits since all of the given figures are only 2 significant digits long. 443.52 g = 440 g</span>
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<img src="https://tex.z-dn.net/?f=PCl_5%20%5Crightleftarrows%20PCl_3%20%2B%20Cl_2" id="TexFormula1" title="PCl_5 \rightleftarrow
Butoxors [25]

<u>Answer:</u> The total pressure of the container will be 2.00 atm

<u>Explanation:</u>

We are given:

Initial moles of phosphorus pentachloride = 1.00 atm

For the given chemical reaction:

PCl_5\rightleftharpoons PCl_3+Cl_2

By Stoichiometry of the reaction:

1 mole of PCl_5 produces 1 mole of PCl_3 and 1 mole of chlorine gas

So, 1.00 atm of PCl_5 will also produce 1.00 atm of PCl_3 and 1.00 atm of chlorine gas when the reaction goes to completion.

Total pressure of the container when the reaction goes to completion  = 1.00 + 1.00 = 2.00 atm

Hence, the total pressure of the container will be 2.00 atm

3 0
2 years ago
Consider the skeletal structure of naphthalein (C10H8), the active ingredient in mothballs. How many double bonds must be added
Greeley [361]

Answer:

four (4)

Explanation:

Naphthalein is an organic compound with formula C 10H 8. It is the simplest polycyclic aromatic hydrocarbon, and is a white crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08 ppm by mass. As an aromatic hydrocarbon, naphthalene's structure consists of a fused pair of benzene rings. It is best known as the main ingredient of traditional mothballs.

The molecule is planar, like benzene. Unlike benzene, the carbon–carbon bonds in naphthalene are not of the same length. The bonds C1−C2, C3−C4, C5−C6 and C7−C8 are about 1.37 Å (137 pm) in length, whereas the other carbon–carbon bonds are about 1.42 Å (142 pm) long. This difference, established by X-ray diffraction is consistent with the valence bond model in naphthalene and in particular, with the theorem of cross-conjugation. This theorem would describe naphthalene as an aromatic benzene unit bonded to a diene but not extensively conjugated to it (at least in the ground state), which is consistent with two of its three resonance structures.

Because of this resonance, the molecule has bilateral symmetry across the plane of the shared carbon pair, as well as across the plane that bisects bonds C2-C3 and C6-C7, and across the plane of the carbon atoms. Thus there are two sets of equivalent hydrogen atoms: the alpha positions, numbered 1, 4, 5, and 8, and the beta positions, 2, 3, 6, and 7. Two isomers are then possible for mono-substituted naphthalenes, corresponding to substitution at an alpha or beta position. Bicyclo[6.2.0]decapentaene is a structural isomer with a fused 4–8 ring system.

Therefore four (4) double bonds will be added to give each carbon atom an octet structure.

8 0
2 years ago
g When 2.50 g of methane (CH4) burns in oxygen, 125 kJ of heat is produced. What is the enthalpy of combustion (in kJ) per mole
Anna [14]

Answer:

-800 kJ/mol

Explanation:

To solve the problem, we have to express the enthalpy of combustion (ΔHc) in kJ per mole (kJ/mol).

First, we have to calculate the moles of methane (CH₄) there are in 2.50 g of substance. For this, we divide the mass into the molecular weight Mw) of CH₄:

Mw(CH₄) = 12 g/mol C + (1 g/mol H x 4) = 16 g/mol

moles CH₄ = mass CH₄/Mw(CH₄)= 2.50 g/(16 g/mol) = 0.15625 mol CH₄

Now, we divide the heat released into the moles of CH₄ to obtain the enthalpy per mole of CH₄:

ΔHc = heat/mol CH₄ = 125 kJ/(0.15625 mol) = 800 kJ/mol

Therefore, the enthalpy of combustion of methane is -800 kJ/mol (the minus sign indicated that the heat is released).

3 0
2 years ago
What volume is occupied by 0.34 moles of Helium gas?
guapka [62]

Answer:

0.65882352941

Explanation:

5 0
2 years ago
Read 2 more answers
How many grams are in 2.5 pound sample
julsineya [31]
About 2,500 grams Ans balkfdoaks; 
5 0
2 years ago
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