Answer:
A
Explanation:
Hhheppppp fffaaast
Mixture of water and LEAD SULPHATE is an example of Homogeneous mixture Select one : True O False
Answer:
False
Explanation:
Lead sulfate is insoluble in water and sinks in water
(sorry if it's wrong)
The 4-4-9 system is used to estimate the number of _______ in food. Question 9 options: A) kilojoules B) calories C) joules D) nutritional Calories
Answer: B) calories
Explanation:
The 4-4-9 system is used to estimate the number of calories in food. Under this system, it is assumed that one gram of Protein, one gram of Carbohydrates and one gram of Fats each contribute 4, 4 and 9 calories respectively to the caloric total.
This means that to find out the number of calories in food, multiply the total grams of proteins by 4, the total grams of carbohydrates by 4 and the total grams of Fats by 9 and then add up the results to find out the caloric contribution of Protein, Carbohydrates and Fats.
Answer:
It's not C calories i put that and missed it
Explanation:
Help for number 9 Please!
Answer:
A..............................
The pressure of a sample of dry air is held constant 2.25 atm while the temperature is
decreased from 100°C to 7.0°C. The original volume of the sample is 43 L. Which of
the following is closest to the final volume of the sample?
A) 3.0L
B) 32L
C) 57 L
D) 610 L
The pressure of a sample of dry air is held constant 2.25 atm while the temperature is decreased from 100°C to 7.0°C. The original volume of the sample is 43 L. 32 L is the closest to the final volume of the sample?
What is Charles's law?A law states that the volume of an ideal gas at constant pressure is directly proportional to the absolute temperature.
Charles’ law:
[tex]\frac{V_1}{T_1}[/tex] = [tex]\frac{V_2}{T_2}[/tex]
The volume and temperature of a fixed amount of gas at a constant pressure are directly proportional.
To use the equation, the temperature must be in Kelvin.
[tex]V_2[/tex] = [tex]\frac{V_1}{T_1} XT_2[/tex]
[tex]V_2[/tex] = 32 L
[tex]V_2[/tex]= 32 L
Hence, the correct answer is B.
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Given the balanced equation representing a reaction
occurring at 101.3kPa and 298K:
2H2 + O2 + 2H2O + 571.6kJ
What is the total amount of energy released when
0.75mol of H2O is produces?
1) 214.4 kJ
3) 285.8 kJ
2) 428.7 kJ
4) 571.6 kJ
whatisthechemicalequationforthereactionofaqueoussodiumhydroxidewithaqueoushydrochloricacid
Answer:
error disconnected
Explanation:
The reaction for the decomposition of ammonia (NH 3 ) can be written as shownIf a student starts with 95.7 g of NH 3 , how many grams of hydrogen (H 2 ) will be produced by the reaction?
Answer:
17.0 g
Explanation:
Step 1: Write the reaction for the decomposition of ammonia
2 NH₃(g) ⇒ N₂(g) + 3 H₂(g)
Step 2: Calculate the moles corresponding to 95.7 g of NH₃
The molar mass of NH₃ is 17.03 g/mol.
95.7 g × 1 mol/17.03 g = 5.62 mol
Step 3: Calculate the moles of H₂ produced from 5.62 moles of NH₃
The molar ratio of NH₃ to H₂ is 2:3. The moles of H₂ produced are 3/2 × 5.62 mol = 8.43 mol.
Step 4: Calculate the mass corresponding to 8.43 moles of H₂
The molar mass of H₂ is 2.02 g/mol.
8.43 mol × 2.02 g/mol = 17.0 g
What reaction type is 1p4+302 = 2p2O3
Answer:
13
Explanation:
When the temperature is 23C, a bottle of gas has a pressure of 5.5atm.Assuming that the volume of the balloon remains constant, what will the
pressure be if the temperature is decreased to 18C?
Answer:
use the formula pressure 1 ÷ temperature 1 = pressure 2 ÷ temp 2
so your equation would look like this,
p2= p1(T2)÷ T1
so p2 =5.5(18)÷23
so it would be 4.304347826
round as you must
A cheetah has been clocked at 112 km/h over a 100-m distance. What is this speed in m/s?
Brainliest will be given to correct answer :)
Chemistry II Help please! Last question on my homework and I'm stuck.
Thank you!
Answer: [tex]\Delta G[/tex] for the reaction is -90kJ
Explanation:
The balanced chemical reaction is,
[tex]2H_2S(g)+SO_2(g)\rightarrow 3S_{rhombic}(s)+2H_2O(g)[/tex]
The expression for Gibbs free energy change is,
[tex]\Delta G=[n\times G_{products}]-[n\times G_{reactants}][/tex]
Putting the values we get :
[tex]\Delta G=[3\times G_f{S,rhombic}+2\times G_f{H_2O}]-[2\times G_f{H_2S}+1\times G_f{SO_2}][/tex]
[tex]\Delta G=[(3\times 0kJ/mol)+(2\times -229kJ/mol)]-[(2\times -34kJ/mol) +(1\times -300kJ/mol)][/tex]
[tex]\Delta G=-90kJ[/tex]
Thus [tex]\Delta G[/tex] for the reaction[tex]2H_2S(g)+SO_2(g)\rightarrow 3S_{rhombic}(s)+2H_2O(g)[/tex] is -90kJ
If an element has 6 protons and its mass number is 14, how many neutrons and electrons does it have?
Answer:
8 neutrons and 6 electrons
Explanation:
Mass number= neutrons + protons
14=x+6
x=14-6
x=8
protons=electrons
6 protons=6 electrons
How many liters of nitrogen gas (N₂) are required to produce 7.5 x 10²⁶ molec NH₃ gas with excess of hydrogen gas at STP?
Answer: The volume of nitrogen gas that is required is 13944 L.
Explanation:
Given values:
Number of molecules of ammonia gas = [tex]7.5\times 10^{26}[/tex]
According to the mole concept:
[tex]6.022\times 10^{23}[/tex] number of molecules are present in 1 mole of a compound
So, [tex]7.5\times 10^{26}[/tex] number of molecules will be present in [tex]\frac{1}{6.022\times 10^{23}}\times 7.5\times 10^{26}=1.245\times 10^3 moles[/tex] of ammonia gas
The chemical equation for the formation of ammonia gas follows:
[tex]N_2 (g) + 3H_2(g) \rightarrow 2NH_3(g)[/tex]
According to the stoichiometry of the reaction:
2 moles of ammonia gas are produced from 1 mole of nitrogen gas
So, [tex]1.245\times 10^3[/tex] moles of ammonia gas will be produced from [tex]\frac{1}{2}\times 1.245 \times 10^3=6.225\times 10^2[/tex] moles of nitrogen gas
At STP conditions:
1 mole of a gas occupies 22.4 L of volume
So, [tex]6.225 \times 10^2[/tex] moles of nitrogen gas will occupy [tex]\frac{22.4 L}{1 mol}\times 6.225\times 10^2 moles=13944 L[/tex] of volume
Hence, the volume of nitrogen gas that is required is 13944 L.
Calculate the pH and pOH of 500.0 mL of a phosphate solution that is 0.285 M HPO42– and 0.285 M PO43–. (Ka for HPO42- = 4.2x10-13 at 25°C)
Answer: when concentrations of acid and base are same, pH = pKa
PH = 12.38 pOH = 1.62
Explanation: pKa= -log(Ka)= 12.38. PH + pOH = 14.00
The pH of the solution is 12.38 and the pOH of the solution is 1.62.
Using the Henderson Hasselbalch equation;
pH = pKa + log [A-]/[HA]
Where;
pKa = - log Ka = -log[ 4.2x10-13] = 12.38
[A-] = [PO43–] = 0.285 M
[HA] = [HPO42-] = 0.285 M
Substituting values;
pH = 12.38 + [ 0.285 M]/[ 0.285 M]
pH = 12.38
But;
pH + pOH = 14
pOH = 14 - 12.38
pOH = 1.62
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3. Jordan built a model of a neutral helium atom.
Nucleus
Proton
Neutron
Electron
What change would fix the mistake in Jordan's model?
How many atoms of H are in 1 mole of NH3
Answer:
Before you use log you have to multiply the answer of 8.66 mol by 6.02⋅1023 by 3 because the answer of 8.66 mol by 6.02⋅1023 gives you the number of ammonia molecules and in each molecules there are 3 hydrogen atoms present.
Explanation:
If a,b,c are in AP & x, y, z are in GP, prove that: x^(b-c).y^(c-a).z^(a- b) = 1
I will report if wrong.
Answer:
b
Explanation:
5. Element X exists as diatomic molecules.
In which group of the Periodic
Table is X placed?
A. Group O
B.
Group I
C.
Group II
D.
Group VII
Element X Exists as diatomic molecules . In which group of the Periodic Table is X placed ?
Group VII
Group VII - elements are Fluorine , Chlorine , Bromine and Iodine .
They exist in diatomic molecules as F2 , Cl2 , Br2 and I2 .
2-methyl-2-butene + hydrogen chloride
This is an electrophilic addition of a hydrogen halide to an alkene.
The pi bond is attacked by the electrophilic H⁺ from the H⁺Cl⁻, resulting in the loss of the double bond and the formation of a tertiary carbocation on C2. A less stable carbocation intermediate with the positive charge on C3 is also formed.
The nucleophilic Cl⁻ then attacks the carbocations, forming the haloalkane products. The major product will be 2-chloro-2-methybutane, where the Cl is bonded to the most substituted C (Markovnikov's rule). The minor product, if you have to worry about it, will be 2-chloro-3-methylbutane. The major product has no stereoisomers to worry about as it's achiral.
The attached image shows the scheme of this reaction. Only the major product is shown.
When a thermometer is heated, the red liquid inside the thermometer moves up. This is mainly because:
A. The red liquid is thin.
B. The molecules of the liquid move faster and get a little further apart.
C. Hot liquid is lighter.
D. The glass of the thermometer gets hot.
The thermometers with red liquid usually depicts a kerosene based column with red dye. It is more safe than mercury thermometer. The red liquid inside the thermometer moves up due to the molecules of the liquid move faster and get a little further apart. The correct option is B.
What is thermometer?The device which is used to measure the temperature is defined as the thermometer. It can measure the temperature of a solid such as food, a liquid like water and a gas like air.
The thermometers which are developed for clinical purposes are called clinical thermometers. It can also measure the temperature of human body. It is a long narrow glass tube which contain a bulb and consists of mercury at the end.
When a thermometer is heated, the molecules present in the liquid inside the thermometer get a little further apart. Because the liquid takes up more space. So the red line moves up in the tube.
Thus the correct option is B.
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What is the purpose of replication?
1-to make an RNA template from DNA
2-to produce copies of a DNA molecule
3-to move mRNA through the ribosome
4-to change the number, type, or order of bases in DNA
Answer:
2-to produce copies of a DNA molecule
Jen and her partner were assigned the Zn/Zn cathode/anode pair which they used to construct their electrolytic cell. They decided to keep the concentration of the corresponding Zn2+ solution constant at 1 M. If Jen ran her cell for 22.8 mins, what current (mA) did she use in order to transfer 9 x 10^-4 moles of electrons?
Answer:
63.2 mA
Explanation:
We all know that:
Current[tex]I = \dfrac{Q}{t}[/tex]
which can be further expressed as:
[tex]I = \dfrac{ne}{t}[/tex]
where;
n = number of electrons
e = charge on electrons
t = time (second)
Then; by replacing the values in the question, we have:
[tex]\dfrac{(9*10^{-4})\times6\times10^{23}\times1.6\times10^{-19}}{22.8\times60}[/tex]
[tex]= 0.06316 A \\ \\ \mathbf{I= 63.2 \ mA}[/tex]
Please please help :/
Answer:
eliptical
Explanation:
25 If the all the white mice are selected against in this environment (eaten by predators) what would happen to the gray mice if the environment were to change quickly to favor white mice? A. B. C. The gray mice would all change to white fur quickly and survive because the genetic traits are recessive and therefore still available in the population's genetics. The gray mice would immediately be eaten by the predators in the area and go extinct. The gray mice could still give birth to white mice if the trait remained in their genetic information and the population could produce white fur offspring which over time would succeed and reproduce causing an increase in white mice. The gray mice would have to move and white mice would move into the area causing the two to quickly develop different genetic traits and to evolve into entirely separate species until the two are no longer the same population. D.
Answer: The gray mice would immediately be eaten by the predators in the area and go extinct.
Explanation:
Natural selection is the differential survival of some members of the population of species which have better phenotypic advantage over others. Such members will survive and reproduce. According to the given situation, white mice were the choice of food for predators and the recessive trait of gray color of gray mice was favoring their survival as they may remain undetected by the predators. But the predators were able to detect the gray mice and changed their food preference from white to gray this way predators will consume all the gray mice and they may extinct in future as it is not possible to change the color of the fur from white to gray so quickly. The adaptation and passage of white trait among the members of the population will occur with a gradual change in successive generations of the population.
How might the population of grasshoppers be affected if the population of owl were to suddenly decrease
Answer:
the population of grasshoppers would rise since there is less owls to eat them.
Explanation:
hope this helps
The percentage composition of a compound expresses the
amount (by weight) of constituent elements in of the
compound
Answer:
The percentage composition of a compound expresses how much of each element is in the compound.
Determine the molecular formula for a compound with
an empirical formula of C2h8N and a molar mass of 46
grams per mole?
Answer:
C2H8N
Explanation:
Hello there!
In this case, since the molecular formula is the complete representation of the considered chemical compound and the empirical one is the smallest possible whole-numbered representation of the former, we infer that the ratio of the molar masses of these two provides the times in which the empirical formula is within the molecular one; for that reason, we first compute the molar mass of the empirical formula:
[tex]MM_{empirical}=12*2+8+14=46g/mol[/tex]
Thus, since the ratio is 46/46=1, we infer that the molecular formula is also C2H8N.
Best regards!
Question 4 point
CH2-CO-THEO
149.65 mole of methane reacts with oxygen to produce carbon dioxide and water, what mass of water is produced
174 gram
425 gram
343 gram
-154 gram
Answer:
[tex]5393.4gH_2O[/tex]
Explanation:
Hello there!
In this case, for the described chemical reaction, we can write:
[tex]CH_4+2O_2\rightarrow CO_2+2H_2O[/tex]
Thus, by considering the 1:2 mole ratio of methane to water, and the molar mass of the latter (18.02 g/mol), the following is useful to calculate the mass of water that is produced:
[tex]149.65molCH_4*\frac{2molH_2O}{1molCH_4} *\frac{18.02gH_2O}{1molH_2O}[/tex]
Which is equal to:
[tex]5393.4gH_2O[/tex]
Which is not among the choices.
Regards!
In addition to Earth, many of the other planets in the Solar System have atmospheres.
O True
O False
the answer is True.
each planet has a significant atmosphere
Answer:
True
Explanation:
bc i know
Make a rule: If you knew the number of valence electrons in a nonmetal atom, how would you determine the valence of the element? (Hint: Ignore hydrogen for now.)
AnswMake a rule : If you knew the number of valence electrons in a nonmetal atom, how would you determine the valence of the element? (Hint: Ignore hydrogen for now.) The group number of the element will tell you the amount of valence electrons. there has to be a full octet in order for it to be stable. 7.er:
Explanation: