Answer:Comparison of Ionic and Covalent Bonds
In an ionic bond, the atoms are bound together by the electrostatic forces in the attraction between ions of opposite charge. ... For example, sodium (Na), a metal, and chloride (Cl), a nonmetal, form an ionic bond to make NaCl. In a covalent bond, the atoms bond by sharing electrons.
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Which of the following are examples of chemical energy being released or stored?
I. A car battery reacting and releasing energy
II. A girl eating a sandwich which helps her move
III. Propane burning on a barbecue
Answer:
it is all of the above
Explanation:
Identify the characteristics of a good recrystallization solvent. Select one or more: Is not an organic liquid with a low boiling point. Dissolves a chemical sample well at high temperatures. Does not dissolve a chemical sample well at high temperatures. Does not dissolve a chemical sample well at low temperatures. Dissolves a chemical sample well at low temperatures.
Answer:
Dissolves a chemical sample well at high temperatures.
Does not dissolve a chemical sample well at low temperatures.
Explanation:
Recrystallization is a purification technique that involves mixing of an impure solid compound with a hot solvent leading to a saturated solution. As this solution cools, the compound to be purified becomes less soluble in the solvent, and pure crystals appear from the solution as the solution cools.
A good recrystallization solvent should
Not dissolve the compound that we want to purify at room temperature Dissolve the compound completely only at the solvent's boiling point Dissolve all the soluble impurities in the sample very well at room temperature.Have a fairly low boiling point such that its boiling point is lower than the melting point of the compound to be purified and evaporates easily when air-drying the sample.The gas in the discharge cell of a laser contains (in mole percent) 11% CO2, 5.3% N2, and 84% He. (a) What is the molar mass of this mixture
Answer:
[tex]MM_{mixture}=9.68g/mol[/tex]
Explanation:
Hello!
In this case, since the molar mass of gaseous mixtures can be determined via a weighted average containing the molar mass of each gas and the mole fraction (mole percent divided by 100) as shown below:
[tex]MM_{mixture}=x_{CO_2}M_{CO_2}+x_{N_2}M_{N_2}+x_{He}M_{He}[/tex]
Now, we plug in to obtain:
[tex]MM_{mixture}=0.11*44g/mol+0.053*28+0.84*4\\\\MM_{mixture}=9.68g/mol[/tex]
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A block with a volume of 20 cm3 has a density of 5 g/cm3. The block is cut into two pieces. One piece has a volume of 15 cm3, and the other piece has a volume of 5 cm3. What are the densities of the two pieces?
Answer:
wouldnt they still have the same density?
Explanation:
for example, the density of iron is 7.874 g/cm^3 no matter how big the piece is. I hope this helps.
Equilibrium occurs in what type of reactions?
A. Catalytic
B. Irreversible
C. Reversible
D. Combustion
Answer:
B. Irreversible
Explanation:
Answer: C Reversible
Explanation:
Founder's Education Quiz
What carpet Burns in a deficiency of O2 a mixture of CO and CO2 forms.Carbon Burns in excess O2 to form only CO2 and CO Burns in excess O2 to form only CO2. Calculate ΔH for C(graphite +1/2O2) →CO(g).
Answer:
Explanation:
From the combustion of carbon, the reactions occurring in limited oxygen conditions are:
[tex]C(graphite) + \dfrac{1}{2}O_{2(g)} \to CO_{(g)}[/tex]
[tex]C(graphite) + O_{2(g)} \to CO_{2(g)}[/tex]
If it occurs in excess, then any leftover CO changes to CO2. i.e.
[tex]C(graphite) + O_{2(g)} \to CO_{2(g)}[/tex] ---- (1)
[tex]CO_{(g)} + \dfrac{1}{2}O_{(g)} \to CO_{2(g)}[/tex] ----- (2)
From (1), the enthalpy change is:
[tex]\Delta H_{rxn1} = \Delta H^0_{fCO_2(g)} - ( \Delta H^0_{f C(graphite)}+ \Delta H^0_{fCO_2(g)}[/tex]
[tex]\Delta H_{rxn1} =-393.5 \ kJ/mol -(0+0)[/tex]
[tex]\Delta H_{rxn1} =-393.5 \ kJ/mol[/tex]
From (2), the enthalpy change is:
[tex]\Delta_{rxn2} = \Delta H^0_{fCO_2(g)} - ( \Delta H^0_{fCO(g)} + \dfrac{1}{2} \Delta H^0_{fO_2(g)})[/tex]
[tex]\Delta_{rxn2} = -393.5 \ kJ/mol -(-110.5 + \dfrac{1}{2}(0))[/tex]
[tex]\Delta_{rxn2} = -283.0 \ kJ/mol[/tex]
Subtracting (2) from (1), we get:
[tex]C(graphite) + O_{2(g)} \to CO_{2(g)} \ \ \ \Delta H_{rxn} = -393.5 \ kJ/mol}[/tex]
[tex]CO_{(g)} + \dfrac{1}{2} O_2(g) \to CO_{2(g)}} \ \ \ \Delta H _{rxn2} = -283.0 \ kJ/mol[/tex]
[tex]C(graphite) + O_{2(g)} \to CO (g) + \dfrac{1}{2}O_{2(g)} \ \ \ \Delta H_{rxn} = -110.5 \ kJ/mol[/tex]
[tex]C(graphite) + \dfrac{1}{2} O_{2(g)} \to CO (g) \ \ \ \Delta H_{rxn} = -110.5 \ kJ/mol[/tex]
The enthalpy change ΔH of the reaction = -110.5 kJ/mol
Which statement describes how the sun gets its light?
A. It bends light.
B. It reflects light.
C. It refracts light.
D. It makes its own light.
Answer:
D
Explanation:
it's a star it has gas and makes it own light
A solution is made by mixing 37.g of thiophene C4H4S and 72.g of heptane C7H16. Calculate the mole fraction of thiophene in this solution. Round your answer to 2 significant digits.
Answer:
0.38
Explanation:
Molar mass of thiophene= 84g/mol
Mass of thiophene = 37g
Number of moles= 37/84= 0.44 moles
Molar mass of heptane= 100 g/mol
Mass of heptane = 72g
Number of moles = 72/100= 0.72 moles
Total number of moles= 0.44 + 0.72= 1.16 moles
mole fraction of thiophene = 0.44/1.16= 0.38
g Determine the oxidation state for each of the elements below. ... The oxidation state of ... phosphorus ... in ... phosphorous tribromide PBr3 ... is ... . The oxidation state of nitrogen in nitrogen gas N2 is . The oxidation state of arsenic in arsenic acid H3AsO4 is .
Answer:
- P in PBr3 is +3.
- N in N2 is 0.
- As in H3AsO4 is +5.
Explanation:
Hello!
In this case, since the determination of the oxidation states is performed by using the well-known charge balances, we can proceed as shown below:
- P in PBr3: Here, bromide ions have an oxidation state of -1, so we follow:
[tex]P^xBr_3^-\\\\x-3=0\\\\x=+3[/tex]
Thus, the oxidation state is +3.
- N in N2: Here, since nitrogen is bonding with nitrogen and it is neutral, we infer its oxidation state is 0.
- As in H3AsO4: Here, oxygen is -2 and hydrogen +1, so we follow:
[tex]H_3^+As^xO_4^{-2}\\\\3+x-8=0\\\\x=8-3\\\\x=5[/tex]
Thus, the oxidation state is +5.
Best regards!
What is Darwin's name for species that do not appear to have changed for millions of years?
Since, the options have not been given the question is incomplete.
What is Darwin's name for species that do not appear to have changed for millions of years?
a.
Dinosaurs
b.
Living fossils
c.
Old souls
d.
Ancient moderns
Answer: b. Living fossil
Explanation:
In 1859 Charles Darwin proposed the term living fossil, that means a species or group of species that had not changed in terms of evolutionary context thus can be useful in tracing the extinct or previously existing forms of life. The examples of the living fossils are horseshoe crabs, ginkgo (Conifers) and tuatara. These group of animals were existed unchanged in the Ordovician, Permian, and Triassic periods respectively with few surviving species.
Answer:
the answer is living fossils so it would be b
Explanation:
how do i know i took the test
A local FM radio station broadcasts at an energy of 6.04E-29 kJ/photon. Calculate the frequency at which it is broadcasting.
Answer:
9.11×10⁷ Hz
Explanation:
From the question given above the following data were obtained:
Energy (E) = 6.04×10¯²⁹ KJ
Frequency (f) =?
Next, we shall convert 6.04×10¯²⁹ KJ to joule (J). This can be obtained as follow:
1 KJ = 1000 J
Therefore,
6.04×10¯²⁹ KJ = 6.04×10¯²⁹ KJ × 1000 J / 1 KJ
6.04×10¯²⁹ KJ = 6.04×10¯²⁶ J
Thus, 6.04×10¯²⁹ KJ is equivalent to 6.04×10¯²⁶ J.
Finally, we shall determine the frequency at which the FM radio station is broadcasting as follow:
Energy (E) = 6.04×10¯²⁶ J
Planck's constant (h) = 6.63×10¯³⁴ Js
Frequency (f) =?
E = hf
6.04×10¯²⁶ = 6.63×10¯³⁴ × f
Divide both side by 6.63×10¯³⁴
f = 6.04×10¯²⁶ / 6.63×10¯³⁴
f = 9.11×10⁷ Hz
Therefore, the frequency at which the FM radio station is broadcasting is 9.11×10⁷ Hz
A sample of g of pure aluminum metal is added to mL of M hydrochloric acid. The volume of hydrogen gas produced at standard temperature and pressure is
Answer:
V = 11.2L are produced
Explanation:
... Sample of 27g of pure aluminium, 3added to 333 mL of 3.0 M HCl..
Based on the chemical reaction:
2Al(s) + 6HCl(aq) → 2AlC₃(aq) + 3H₂(g)
Where 3 moles of hydrogen are produced when 6 moles of hydrochloric acid reacts with 2 moles of Al.
To solve this question, we need to determine limiting reactant converting each reactant to moles. With limiting reactant and the chemical reaction we can find moles of hydrogen and its volume at STP (T=273.15K; P=1atm), thus:
Moles Al-Molar mass: 26.98g/mol-:
27g * (1mol / 26.98g) = 1mol of Al
Moles HCl:
333mL = 0.333L * (3mol/L) = 1mol HCl
For a complete reaction of 1 mole of HCl are required:
1mol HCl * (2mol Al / 6mol HCl) = 0.333 moles of Al. As there is 1 mole of Al, Al is in excess and HCl is limiting reactant.
Moles of Hydrogen produced are:
1mol HCl * (3 moles H₂ / 6 mol HCl) = 0.5moles H₂ are produced.
Using ideal gas law:
PV = nRT
V = nRT/P
Where V is volume
n are moles: 0.5mol
R is gas constant: 0.082atmL/molK
T is absolute temperature: 273.15K
P is pressure: 1atm.
Solving for V:
V = 0.5mol*0.082atmL/molK*273.15K / 1atm
V = 11.2L are produced
How many atoms are in .938 moles of CO2?
Answer: 1.695x10^24 atoms
Explanation: 0.938 moles CO2 = 0.938xavogadro number molecules CO2, so number of atoms = 3x0.938x6.02214076x10^23 = 1.695x10^24
What element corresponds to period 5, group 2
Answer:
Strontium is the second element placed in the 5th period
Hope this will help you if not so advance sorry :)
Determine the molar mass of Cao
Answer:
Molar mass of CaO
(40 + 16)g
= 56g
hope it helps you
A 52 gram sample of an unknown metal requires 714 Joules of energy to heat it from
30.5◦C to 82◦C. What is the specific heat of
this metal?
Answer in units of J/g ·
◦ C.
Answer: Approximately [tex]0.267 \frac{\text{J}}{\text{g}^{\circ}\text{C}}[/tex]
===================================================
Work Shown:
We have the following variables
Q = 714 joules = heat requiredm = 52 grams = massc = specific heat = unknown[tex]\Delta t[/tex] = 82-30.5 = 51.5 = change in temperaturenote: the symbol [tex]\Delta[/tex] is the uppercase Greek letter delta. It represents the difference or change in a value.
Apply those values into the formula below. Solve for c.
[tex]Q = m*c*\Delta t\\\\714 = 52*c*51.5\\\\714 = 52*51.5*c\\\\714 = 2678*c\\\\2678*c = 714\\\\c = \frac{714}{2678}\\\\c \approx 0.26661687826737\\\\c \approx 0.267\\\\[/tex]
The specific heat of the unknown metal is roughly [tex]0.267 \frac{\text{J}}{\text{g}^{\circ}\text{C}}[/tex]
How would a long period without sunlight affect the food web?
It would cause consumers to consume more food.
It would have no effect on the food web.
It would stop decomposers from breaking down matter.
It would stop producers from producing food.
Answer: it would stop producers from producing food.
Explanation: why? Without the action of the producers to turn sunlight into food, the producers would die, and consumers that rely on them would lose their food source and die too.
Answer:
It would stop producers from producing food
Explanation:
Producers would die, and if producers died, consumers would die too.
Hope this helps
If one force on an object is 5 N upward and the other is 10 N downward what is the objects motion?
To solve this we must be knowing each and every concept related to force. Therefore, the objects motion will be towards downward with a force of 5 N.
What is force?A force is an outside entity that has the power to alter a body's state of rest or motion. It has a direction and a magnitude. The point where forces are applied is determined by the the force's direction as well as the application of the force.
Newton and dyne units are used to measure the force exerted on an item. When using the centimeter kilogram second system of units, force is measured in dynes (CGS unit). In the common international system of units, it is denoted by the letter Newton (N) (SI unit).
upward force=5 N
downward force= 10 N
total force acting on body=downward force-upward force
= 10 N - 5 N
=5 N downward force
The objects motion will be towards downward with a force of 5 N.
Therefore, the objects motion will be towards downward with a force of 5 N.
To learn more about force, here:
https://brainly.com/question/13014979
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What is a molecule contains the genetic instructions for the development and functioning of all living organisms found in the nucleus of a cell
What is the molecular formula for a compound with a molar mass of 42.08g/mol and an empirical formula of ch2
Answer:
[tex]C_3H_6[/tex]
Explanation:
Hello!
In this case, since the empirical formula is the smallest representation of the molecular formula, it is known that the times in which the empirical formula is into the molecular formula is a whole number and is computed by dividing the molar mass of the molecular formula by that of the empirical formula as shown below:
[tex]\frac{42.08g/mol}{12.01+1.01x2}= \frac{42.08g/mol}{14.03g/mol}=3[/tex]
Thus, the molecular formula times the empirical formula by 3 to obtain:
[tex]C_3H_6[/tex]
Regards!
Give the IUPAC name for each compound.
Answer:
a. 1-fluoro-3,3,4-trimethyl-pentane.
b. 1-iodo-3-ethyl-2-methyl-hexane.
c. 1,3-dichloro-5-dimethyl-hexane.
d. 1-bromo-3-methyl-cyclopentane.
Explanation:
Hello!
In this case, according to the IUPAC rules for the listed alkyl halides, we first need to name the halogens (considering periodic order) then alkyl radicals and finally the parent chain; thus, the names are given below:
a. 1-fluoro-3,3,4-trimethyl-pentane.
b. 1-iodo-3-ethyl-2-methyl-hexane.
c. 1,3-dichloro-5-dimethyl-hexane.
d. 1-bromo-3-methyl-cyclopentane.
e. 5-chloro-1-bromo-1,1,5-trimethyl-pentane (radicals are not clear).
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Which of these is not a property of minerals?
A) Clevage
B) Fracture
C) Color
D) Smell
What makes this inauguration different from the past?
Answer:
there's just a lot of drama around grumpy trumpy's StOlEN eLecTiOn which are all just fake claims. all his hardcore followers are brainwashed into believing anything he says, so people (especially people who are inside the capitol) fear that trump's followers might incite violence AGAIN even after they broke into the Capitol on the 6th.
That's why they have the National Guard and thousands of people to keep the building secure during Biden's Inauguration.
hope this helps!
How many milliliters of 60% carbonic acid must be mixed with how many milliliters of 15% carbonic acid to make 650 milliliters of a 38% carbonic acid solution
Answer:
348.9 mL of the 60% solution and 251.1 mL of the 15% solution.
Explanation:
First, we calculate how many mililiters of pure carbonic acid are there in 650 mL of a 38% solution:
650 mL * 38/100 = 247 mLThen we can express the sum of both initial solutions as:
1) x * 60/100 + y * 15/100 = 247for the volume of carbonic acid; and
2) x + y = 600 mLFor the volume of the solutions.
We now have a system of two equations and two unknowns (x is the volume of the 60% solution and y is the volume of the 15% solution).
We express x in terms of y in equation 2):
x = 600 - yAnd replace x in equation 1):
(600 - y) * 60/100 + y * 15/100 = 247360 - 0.6y + 0.15y = 247-0.45y = -113y = 251. 1 mLFinally we calculate x using equation 2):
x + 251.1 = 600x = 348.9 mLHow are molecules built?
All of these
Phase Changes
Atomic Rays
Bonding
1
Answer:
By bonding due to the attractive forces
determine the molar mass for ammonia (NH3) in g/mol.
Answer:
17.031 g/mol
Explanation:
How can both the pitcher and the glass contain the same volume of iced
tea?
Answer: $6,600[tex]\alpha \sqrt[n]{x} \lim_{n \to \infty} a_n[/tex]
Explanation:
What does it mean to be an invertebrate?
invertebrate is a animal that does not have a back bone but may have a exoskeleton examples could be earthworm, jellyfish, snail and a spider because it has a exoskeleton a hard outer shell hope this helps
Vertebrates have a back bone like sea turtles , fish ,foxes and humans.
what element is in group 13, period 4
Answer:
Gallium
Explanation:
Answer:
Gallium
Explanation:
Which feature does an iron metal have?