Answer:
cvbn
Explanation:
Fossil fuels are considered to be:
a.
irreplaceable resources
c.
renewable resources
b.
nonrenewable resources
d.
hazardous wastes
Please select the best answer from the choices provided
A
B
C
D
HELP ;-;
Vanillin, C8H8O3, the principal component of vanilla beans, is very similar to glucose, C6H12O6 a type of sugar. Brittany Spears has a life threatening allergy to vanillin. After one of her concerts she was found dead in her dressing room. A glass lined with a white powder was found smashed on the floor next to her. Police think the glass was lined with vanillin suggesting she was murdered. A 2.54 g sample of this powder underwent carbon-hydrogen analysis. It’s combustion was found to produce 5.875 g of CO2 (g) and 2.41 g of H2O(g) . Find the empirical formula of this compound and determine if Brittany may have been poisoned?
b) Is this evidence enough to conclude for certain that the identity of the powder on the glass is indeed vanillin? Why or why not?
Answer:
The empirical formula is: CH2
Th powder is not vainillin
Explanation:
We can find empirical formula of a compound CₐHₓOₙ knowing that moles CO2 = Moles C, 2 Moles H2O = Moles H and that we can find the mass of oxygen by the difference of masses of the atoms:
Moles C = Moles CO2 -Molar mass: 44.01g/mol-
5.875g * (1mol/44.01g) = 0.1335 moles C * (12.01g/mol) = 1.60gC
Moles H2O and moles H -Molar mass: 18.01g/mol-
2.41g H2O * (1mol / 18.01g) = 0.1339 moles H2O * (2mol H / 1mol H2O) =
0.2676 moles H * (1g/mol) = 0.27g H
The empirical formula of this compound is the ratio of C:H:
0.2676 moles H / 0.1335 moles C = 2
The empirical formula is:
CH2
In vainillin, the moles of Carbon = Moles of Hydrogen. the experiment shows the moles of hydrogen are twice the moles of carbon. Thus, the powder is not vainillin
A circuit is set up with two parallel resistors, each of a resistance of 250Ω.
b. If another resistor of resistance 300Ω is added in series with these two parallel resistors, what is the total
resistance?
c. If a voltage of 120V is put across the circuit in b, what will the current be in the circuit?
Answer:
425 and 0.28A
Explanation:
Resistance for resistors in parallel
1/ R = 1/250 +1/250
=0.008
R = 1/ 0.008 = 125
Total resistance
R= 125+ 300
=425
...
V= IR
I= V/R
I = 120/425
= 0.28 A
If a student has 125 mL of a 4.00 M CuSO4 solution and needs a 1.50 M solution, what volume do they need to dilute it to?
Answer:
333.3mL
Explanation:
Using the formula as follows:
C1V1 = C2V2
Where;
C1 = initial concentration (M)
C2 = final concentration (M)
V1 = initial volume (mL)
V2 = final volume (mL)
According to the information provided in this question,
C1 = 4.00M
C2 = 1.50M
V1 = 125mL
V2 = ?
Using C1V1 = C2V2
4 × 125 = 1.5 × V2
500 = 1.5V2
V2 = 500/1.5
V2 = 333.3mL
Therefore, the CuSO4 solution needs to be diluted to 333.3mL to make 1.50 M solution.
True or false:
The following equation is balanced properly: 6CO2 + 6H2O → C6H12O6 + O2
The table shows the specific heat of four substances—brick, dry soil, paper, and water. If all four substances were exposed to sunlight for the same amount of time, which substance would heat up the fastest?
Answer:
Brick
Explanation:
.................
. A circuit is set up with two parallel resistors, each of a resistance of 250Ω. a. What is the total resistance for this circuit?
Answer:
125 ohms
Explanation:
since they're parallel we do
1/total resistance = (1/250 ohms) + (1/250 ohms)
then you get 2/250 ohms
then you flip it so it's equal to total resistance/1
250÷2= 125
In a solution containing 21.2 g sodium carbonate in 1.50 L of solution, calculate
the concentration of the sodium and carbonate ions.
Answer:
0.13 molL-1
Explanation:
We must first obtain the number of moles of sodium carbonate as follows;
Number of moles = mass/molar mass
Number of moles = 21.2 g/106 g/mol
Number of moles= 0.2 moles
Number of moles = concentration × volume
Volume = 1.50 L
Concentration = number of moles/volume
Concentration = 0.2 moles/1.5 L
Concentration = 0.13 molL-1
ASAAAP HURRRY PLS!!!
Where in aerobic respiration is the largest amount of energy produced?
A)
At the beginning of the cycle, when glucose is oxidized to pyruvate.
B)
At the end of the electron transport chain, when oxygen is reduced.
C)
At the end of the electron-transport chain, when oxygen is oxidized.
D)
At the beginning of the electron transport chain, when oxygen is oxidized.
Magnesium is added to dilute hydrochloric acid. This makes bubbles of hydrogen and a colorless solution of magnesium chloride. Write down the name of one of the products of this reaction.
Answer:
The products are already in the question Hydrogen gas and Magnesium Chloride
Explanation:
2Mg +2HCl₂ = 2MgCl₂ + H₂ balanced equation if you need it
When any metal react with acid then salt and hydrogen gas is formed. Hydrogen gas and Magnesium Chloride are formed when Magnesium is added to dilute hydrochloric acid.
What is chemical reaction?Chemical reaction is a process in which two or more than two molecules collide in right orientation and energy to form a new chemical compound. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, double displacement reaction.
The products are Hydrogen gas and Magnesium Chloride. The balanced equation can be written as
Mg +2HCl[tex]\rightarrow[/tex] MgCl₂ + H₂
This makes bubbles of hydrogen and a colorless solution of magnesium chloride.
Therefore Hydrogen gas and Magnesium Chloride are formed when Magnesium is added to dilute hydrochloric acid.
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what two factors affect the pressure in a solid
There are four main factors that can affect the reaction rate of a chemical reaction:
Reactant concentration. Increasing the concentration of one or more reactants will often increase the rate of reaction. ...
Physical state of the reactants and surface area. ...
Temperature. ...
Presence of a catalyst.
please make me brainlist answer
Do you think it matters if you
report 150 grams as 150
grams or 150.0 grams? Do
they mean the same thing?
Why or why not?
Answer:
yes I do think they mean the same thing
Explanation:
150 grams and 150 grams is the same thing and adding 0 to the end of a decimal does not change its value, you could even put 150.0000000 grams and it would still be equivalent to the other numbers
can someone answer this please
Question 12 of 15
Matter can undergo chemical reactions and nuclear reactions. Which
statement is true for both types of reactions?
A. The reactants are changed to form the products.
B. The reactants can be elements or compounds.
C. The products can be elements or compounds.
D. The products can be the same as the reactants.
Answer:
A. The reactants are changed to form the products.
Explanation:
Chemical reactions are reactions that involves a change in the chemical composition of substances involved while a nuclear reaction is the process of fusing together or splitting the nucleus of an atom. According to this question, matter is said to undergo both types of reaction.
However, one similarity in both chemical and nuclear reactions is that substances called REACTANTS are changed to form PRODUCTS. In nuclear reaction, the atoms joined or split are the reactants while the ones formed are the products.
Answer: A
Explanation:
Directions: Each set of lettered choices below refers to the numbered statements immediately following it. Select the one lettered choice that best fits each statement. A choice may be used once, more than once, or not at all in each set. The following questions refer to the below molecules: (A) CO2 (B) H2O (C) CH4 (D) C2H4 (E) PH3 The molecule that has trigonal pyramidal geometry
Answer:
The given molecules are:
(A) CO2 (B) H2O (C) CH4 (D) C2H4 (E) PH3
Which one has trigonal pyramidal geometry?
Explanation:
According to VSEPR (valence shell electron pair repulsion) theory, a molecule with a central atom having hybridization sp3 and with one lone pair of electrons has trigonal pyramidal geometry.
Among the given molecules,
CO2 has central atom carbon with sp hybridization without lone pairs.
So, it is a linear molecule.
H2O, the central atom is oxygen with sp3 hybridization and oxygen has two lone pairs. So, its geometry is V-shape or bent.
CH4 has central atom carbon with sp3 hybridization and no pairs.
So, its geometry is tetrahedral.
C2H4 ethene has carbon atoms as the central atoms with sp2 hybridization and carbon has no lone pairs.
So, its geometry is trigonal planar.
Answer:
PH3 has central atom P with sp3 hybridization.
P has one lone pair on it.
Hence, the geometry of PH3 is trigonal pyramidal.
1. What is the volume of 4.00g of aluminum at STP?
Answer:
22.4cm³
Explanation:
Avogadro's law shows that Avogadro's volume is 22.4
Cells can regulate different processes in two ways. They can turn on and off the genes that make enzymes, or they can
A)
increase the activation energy of a reaction.
B)
increase the amount of energy needed to carry out the preferred process.
C)
regulate the enzymes that are already made.
D)
decrease the amount of energy needed to carry out the preferred process.
If you have 3 moles of a gas at a pressure of 2.5 atm and a volume of 8 liters, what is the temperature?
a. 57.86 K
b. 0.81 K
c. 25 K
d. 81.26 K
Answer:
d
Explanation:
pv=nrt
2.5×1.01×10^5×8×10^-3=3×8.31×T
T=
The value of the temperature can be determined by ideal gas law and the temperature will be 0.81 K.
What is temperature ?The average kinetic energy of particular atoms and molecules in a system is measured by the temperature.
What is ideal gas Law?
Ideal gas law explain the relationship between pressure. temperature and volume.
Ideal gas law can be expressed as, PV=nRT.
where, P is pressure. V is volume , n is number of moles ,R is gas constant and T is temperature. It is given that, n= 3 mole, P = 2.5 atm, V = 8 L, T=?, R = 8.31.
Calculation of temperature by using ideal gas law is shown as:
Now, put the values of given data in ideal gas law equation.
T = PV/nR
=2.5×8/3×8.32
= 0.81 K
Therefore, the temperature will be 0.81K.
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What species is reduced in the reaction below?
Zn° + 2 Ag+ → Zn2+ + 2 Agº?
A) Znº
B) Agº
C) Zn2+
D) Ag+
Answer: The correct option is D) [tex]Ag^+[/tex]
Explanation:
The oxidation reaction is defined as the reaction in which a chemical species loses electrons in a chemical reaction. It occurs when oxidation number of a species increases.
A reduction reaction is defined as the reaction in which a chemical species gains electrons in a chemical reaction. It occurs when oxidation number of a species decreases.
For the given chemical reaction:
[tex]Zn^0+2Ag^+\rightarrow Zn^{2+}+2Ag^0[/tex]
On the reactant side:
Oxidation number of Zn = 0
Oxidation number of Ag = +1
On the product side:
Oxidation number of Zn = +2
Oxidation number of Ag = 0
As the oxidation number of Ag is decreasing from +1 to 0. Thus, [tex]Ag^+[/tex] is getting reduced.
Hence, the correct option is D) [tex]Ag^+[/tex]
Please somone help me with a chemistry question brainliest to whoever answers correctly and 20 points
Answer:
3132 is the answer
Explanation:
3BaCl2 + Al2S3 → 3BaS + 2AlCl3
Answer:
Explanation:
Hope this helps u !!
calculate the pressure in atm of .68 mol of H at 298K and occupying 4.5 L
Answer:
3.7 atm
General Formulas and Concepts:
Atomic Structure
MolesGas Laws
Ideal Gas Law: PV = nRT
P is pressureV is volumen is number of molesR is gas constantT is temperatureExplanation:
Step 1: Define
Identify variables
[Given] n = 0.68 mol H
[Given] T = 298 K
[Given] V = 4.5 L
[Given] R = 0.0821 L · atm · mol⁻¹ · K⁻¹
[Solve] P
Step 2: Find Pressure
Substitute in variables [Ideal Gas Law]: P(4.5 L) = (0.68 mol)(0.0821 L · atm · mol⁻¹ · K⁻¹)(298 K)Multiply [Cancel out units]: P(4.5 L) = (0.055828 L · atm · K⁻¹)(298 K)Multiply [Cancel out units]: P(4.5 L) = 16.6367 L · atmIsolate P [Cancel out units]: P = 3.69705 atmStep 3: Check
Follow sig fig rules and round. We are given 2 sig figs as our lowest.
3.69705 atm ≈ 3.7 atm
Which type of bond is found in an alkane?
O A. Double only
B. Single and double
O C. Single only
O D. Single and triple
Considering the definition of alkanes, single bonds are found in an alkane.
Definition of AlkanesAlkanes are a class of hydrocarbons (compounds containing only carbon and hydrogen) that are made up of a variable number of carbon atoms joined together by single bonds. In turn, each carbon atom bonds to hydrogen atoms, which may eventually be replaced by other atoms or functional groups.
In other words, alkanes are open or closed chain molecules that are linked by simple bonds.
Alkanes are saturated hydrocarbons because the bonds between carbon atoms are simple and stable. And as mentioned, the hydrogen atoms bonded to each carbon atom can be replaced by other atoms, such as halogens (fluorine, bromine, chlorine) or various groups or “radicals”. In the latter case, the structure becomes more complex giving rise to branched alkanes.
SummaryIn summary, single bonds are found in an alkane.
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Answer: C) single only
Explanation:
just got it right
What is stoichiometry?
Answer:
hope it help u !!!!
Explanation:
Stoichiometry is the relationship between the relative quantities of substances taking part in a reaction or forming a compound, typically a ratio of whole integers
Beryllium is in Group 2.
What does this tell you about the electronic structure of beryllium?
Answer:
[He] 2s²
Explanation:
In explosive combustion the rapid expansion of --------------- causes explosion and the production of ------------------
Answer:
Volume; high temperature and pressure
Explanation:
In an explosive combustion the rapid expansion of the volume causes explosion and the production of high temperature and pressure.
The substance is usually in a confined place and the expansion usually reaches a breaking point in which it is expelled from the space usually accompanied with a loud noise and high amount of temperature and pressure change thereby releasing its gas constituents.
Using the periodic table, choose the more reactive nonmetal.
Br or As
Reactivity of non-metals depend on their ability to gain electrons. So, smaller is the size of a non-metal more readily it will attract electrons because then nucleus will be more closer to valence shell. ... Hence, Br is the non-metal which will be more reactive than At.
Answer:
br is more reactive than as
Identify the total number of moles involved in the reaction
2C4H10(g) + 13 O2(g) – 10 H2O(g) + 8 CO2(g)
Answer:
33 moles
Explanation:
The given chemical reaction is 2C₄H₁₀(g) + 13 O₂(g) → 10H₂O(g) + 8CO₂(g)
The number of moles of each reactant are as follows;
Butane, C₄H₁₀ = 2 moles of (g) + 13 (g) → 10H₂O(g) + 8CO₂(g)
Oxygen gas, O₂ = 13 moles
Water, H₂O = 10 moles
Carbon dioxide, CO₂ = 8 moles
The total number of moles, n = (2 + 13 + 10 + 8) = 33
∴ The total number of moles involved in the reaction, n = 33 moles.
Please help I have chemistry final
Answer:
Tick
1
2
4
6
Explanation:
magnesium is not a good conductor has some free electrons but it is not used that much in the industries because of other better alternatives.
You can tick number 5 as wlee. Good luck
Answer:
the answer is a
Explanation:
it'sa silver-white an earth metal
write an equation for the reaction in which hydrochloric acid neutralises sodium hydroxide
Answer:
ok
Explanation:
A salt is a neutral ionic compound. Let's see how a neutralization reaction produces both water and a salt, using as an example the reaction between solutions of hydrochloric acid and sodium hydroxide. The overall equation for this reaction is: NaOH + HCl -> H2O and NaCl.
what happened to the ionization energy of hydrogen"H" when its electron affinity
