Answer:
The FitnessGram™ Pacer Test is a multistage aerobic capacity test that progressively gets more difficult as it continues. The 20 meter pacer test will begin in 30 seconds. Line up at the start. The running speed starts slowly, but gets faster each minute after you hear this signal. [beep] A single lap should be completed each time you hear this sound. [ding] Remember to run in a straight line, and run as long as possible. The second time you fail to complete a lap before the sound, your test is over.
HELP!! Which of the following phase changes occur at point B on the phase diagram shown below?
Boiling
Condensation
Freezing
Sublimation
Answer:
freezing
Explanation:
because condensation is gas to liquid boiling is liquid to gas and sublimation is solid to gas
What's the IUPAC name O || CH3CH2CH2CH2COCH3
Answer:
2-hexanone
Explanation:
Since we are asked to find the IUPAC Name;
First thing we need to do is to identify the functional group.
In this case it is ketone group, because the formula for ketone is CnH2nO.
Thus, the last suffix will be -one.
Secondly, secondly, we will find the longest carbon chain which in this case is 6. Six has the prefix "hex-"
The Formula has no branches group.
Thus, we can call it 2-hexanone
What does the mass of an object measure?
a: amount of matter it contains .
b: force of gravity acting on it.
c: amount of water it displaces.
d: amount of space it takes up.
Answer:
the amount of matter it contain
Calculate the number of hydrogen atoms in 33.0 g CH4
Answer:
The number of hydrogen atoms is 4.96x10²⁴.
Explanation:
The number of atoms can be found with the following equation:
[tex] n = N*\eta_{H} [/tex]
Where:
N: is the Avogadro's number = 6.022x10²³ atoms/mol
η: is the number of moles of hydrogen
n: is the number of hydrogen atoms
First, we need to find the number of hydrogen moles. The number of moles of CH₄ is:
[tex] \eta_{CH_{4}} = \frac{m}{M} [/tex]
Where:
m: is the mass of methane = 33 g
M: is the molar mass of methane = 16.04 g/mol
[tex] \eta_{CH_{4}} = \frac{33 g}{16.04 g/mol} = 2.06 mol [/tex]
Now, since we have 4 hydrogen atoms in 1 mol of methane, the number of moles of hydrogen is:
[tex] \eta_{H} = 2.06\: mol\: CH_{4}*4 \frac{mol\: H}{mol \: CH_{4}} = 8.24 mol [/tex]
Hence, the number of hydrogen atoms is:
[tex]n = N*\eta_{H} = 6.022 \cdot 10^{23} \: atoms/mol*8.24 mol = 4.96 \cdot 10^{24} atoms[/tex]
Therefore, the number of hydrogen atoms is 4.96x10²⁴.
I hope it helps you!
Which statement is true about the atoms in helium gas?
They have strong attractions to one another.
They travel in circular paths.
They are arranged in an orderly pattern.
They are not closely packed.
Answer: The answer is they are not closely packed
Explanation: HOPE THIS HELPS!!
an oil drum weights 11.8kg. when it is filled, octane it weighs 55.32kg. how many molecules of pentane c5h12 exist in this oil drum?
Question: an oil drum weights 11.8kg. when it is filled, pentane it weighs 55.32kg. how many molecules of pentane c5h12 exist in this oil drum?
Answer:
3.64×10²⁶ molecules
Explanation:
Applying,
n = M/M.M................... Equation 1
Where n = number of moles of pentane, M = mass of pentane, M.M = reacting mass of pentane
From the question,
Given: M = 55.32-11.8 = 43.52 kg = 43520 g
Constant: M.M of octane (C₅H₁₂) = [(12×5)+(1×12)] = 60+12 = 72 g/mol
Substitute these values into equation 1
n = 43520/72
n = 604.44 moles
Therefore,
number of molecules = n×(6.02×10²³)
number of molecules = 604.44(6.02×10²³)
number of molecules = 3.64×10²⁶ molecules
Select all of the following reactions that are endothermic.
½N 2(g) + 3/2H 2(g) → NH 3(g) + 11.0 kcal/mole
H 2(g) + ½O 2(g) → H 2O(g), ΔH = -57.83 kcal/mole
½N 2(g) + O 2(g) + 8.1 kcal → NO 2(g)
½N 2(g) + ½O 2(g) → NO(g), ΔH = +21.6 kcal/mole
NH 3(g) → ½N 2(g) + 3/2H 2(g), ΔH = +11.0 kcal/mole
Answer:
½N 2(g) + O 2(g) + 8.1 kcal → NO 2(g)
½N 2(g) + ½O 2(g) → NO(g), ΔH = +21.6 kcal/mole
NH 3(g) → ½N 2(g) + 3/2H 2(g), ΔH = +11.0 kcal/mole
General Formulas and Concepts:
Thermochemistry
Endothermic vs ExothermicEnthalpyExplanation:
An endothermic reaction would have heat or energy gained in the final stage of the reaction.
This means that our enthalpy would be positive and heat/energy would be added as a reactant.
Out of all the answer choices, we see that only these have heat/energy added in the reactant side or the enthalpy being positive:
½N 2(g) + O 2(g) + 8.1 kcal → NO 2(g)
½N 2(g) + ½O 2(g) → NO(g), ΔH = +21.6 kcal/mole
NH 3(g) → ½N 2(g) + 3/2H 2(g), ΔH = +11.0 kcal/mole
Topic: AP Chemistry
Unit: Thermochemistry
movement of water molecules without the use of energy
The answer is ‘Passive Transport’
movement of molecules without the use of energy is due to the shrinkage of water
Sodium and chlorine combine to form table salt.
2Na(s) + Cl2(g) → 2NaCl(s)
Does this reaction obey the law of conservation of mass?
Answer:
yes it does
Explanation:
because the ratios on the reactants and products are equal
The reaction 2Na(s) + Cl₂(g) → 2NaCl(s) obeys the law of conservation of mass.
Yes, this reaction obeys the law of conservation of mass. The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction; it is only rearranged.
In the given reaction, we have 2 sodium atoms (Na) on the left side and 2 sodium atoms (Na) on the right side. Similarly, we have 2 chlorine molecules (Cl₂) on the left side and 2 chlorine atoms (Cl) on the right side. Therefore, the number of atoms of each element is balanced on both sides of the reaction.
Additionally, the total mass of the reactants (2Na + Cl₂) is equal to the total mass of the product (2NaCl). The coefficients in the balanced equation represent the stoichiometric ratios, ensuring that the mass is conserved.
Hence, the reaction 2Na(s) + Cl₂(g) → 2NaCl(s) obeys the law of conservation of mass.
Learn more about law of conservation of mass from the link given below.
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cuales son los numeros cuanticos con ejemplo
CH3 CH2 CH2 OH + H2SO4
Get the product and answer the following questions :
I. A + HCl
II. A --> Combustion ( what product does it form. Write out the equation )
III.A ---> Hydrogenation (what product does it form. Write out the equation )
Note : A represents the product gotten from the reaction between
CH3 CH2 CH2 OH and H2SO4
Answer:
propene and hydrogen is product
When propanol is heated with concentrated sulphuric acid at 443 K, dehydration takes place and prop-1-ene is formed. In this reaction concentrated sulphuric acid acts as a dehydrating agent.
I. A + HCl gives )-gives 2-chloropropane
II. A --> Combustion ( what product does it form. Write out the equation propene ozonide
III.A ---> Hydrogenation (what product does it form. Write out the equation )propanol
Which equation is balanced?
2Al+3O2→Al2O3
2Na+F2→2NaF
Mg+O2→2MgO
2Al+F2→2AlF3
the 1st one is balanced, the 2nd isn't (the number of Mg differs from left 1 to right 2).
The third is also not balanced, 2 F left,2*3=6 on the right
describe one displacement reaction that is useful and explain why it is useful
Answer:
carbon reaction with iron from its oxide. Why?? Because it is largely used in extraction of metals. It is used in acid indigestion.
6. The melting point of iodine is 114°C and the boiling point is 183°C. What state will Iodine be at each of these temperatures:
70°C –
210°C –
185°C –
127°C –
0°C –
Answer:
the answer is known as 210°c
Biết độ tan s của AgNO3 ở 60 độ C là 525 gam ở 10 độ C là 170 gam tính lượng AgNO3 tách ra khi làm lạnh 2.500g dung dịch AgNO3 bão hòa ở 60 độ C xuống 10 độ C
Answer:
Can you translate for me please
what happens to the atomic size of elements on moving from left to right in a period of modern periodic table?
Answer: the atomic size will decrease
Explanation:
Answer:
It will remain the same because it is moving up and down to and fro it can not increase nor decrease or else will become an ion
what are the byproduct obtained during fermentation of glucose
plz help me , I will follow u ,rate u 5 star,give u like and also give u branist.plz pls help me
Answer:
during the fermentation of glucose carbon dioxide and alcohol are produced
I hope this helps
Which one is wrong I did them but it’s saying I got partial credit
A hot metal plate at 150°C has been placed in air at room temperature. Which event would most likely take place over the next few minutes? Molecules in both the metal and the surrounding air will start moving at lower speeds. Molecules in both the metal and the surrounding air will start moving at higher speeds. The air molecules that are surrounding the metal will slow down, and the molecules in the metal will speed up. The air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down.
Answer:
not goin to be rude but I don't even get the question??
What is the purpose of the lab
Earth is approximately 1.5 x 10^8 km from the sun the. How far is earth from the sun meters
Answer:
[tex]{ \tt{1 \: km = 1000m}} \\ { \tt{1.5 \times {10}^{8} km = (\frac{1.5 \times {10}^{8} \times 1000 }{1} )m}} \\ = 1.5 \times {10}^{11} \: metres[/tex]
I need help on this question pleas label
Answer:
we will solve your Quiz
Explanation:
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How many sodium (NA) Atoms are in Methylene?
None
Explanation:
methylene is an organic compound comprising and of One carbon and two hydrogens
Hii pls helpnme to write out the ionic equation
Answer:
CO32-(aq) + 2H+(aq) → CO2(g) + H2O(l)
Explanation:
According to this question, sodium carbonate reacts with sulfuric acid to form aqueous sodium sulfate, carbon dioxide and water. The balanced chemical equation is as follows:
Na2CO3(aq) + H2SO4(aq) → Na2SO4(aq) + CO2(g) + H2O(l)
- Next, split compounds that are aqueous into ions.
2Na+(aq) + CO32-(aq) + 2H+(aq) + SO42-(aq) → 2Na+(aq) + SO42-(aq) + CO2(g) + H2O(l)
- Next, we cancel out the spectator ions, which are ions that remain the same in the reactants and products side of a chemical reaction. The spectator ions in this equation are 2Na+(aq) and SO42-(aq).
CO32-(aq) + 2H+(aq) → CO2(g) + H2O(l)
- Hence, the balanced ionic equation is as follows:
CO32-(aq) + 2H+(aq) → CO2(g) + H2O(l)
PLZZZ HELP ASAP
In the following beta decay problem, C = ___________.
C = Ca
A = 20
B = 42
What happens in beta decay?₁₉⁴²K → ⁴²₂₀Ca + ⁰₋₁e
There is an addition of one electron. The atomic number increases by one.
Positrons or electrons make up beta particles (electrons with positive electric charge, or antielectrons). In a nucleus with an excessive number of protons or neutrons, beta decay happens when one of the protons or neutrons is converted into the other. A neutron degrades into a proton, electron, and antineutrino in beta minus decay. A proton degrades into a neutron, a positron, and a neutrino in beta plus decay.
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which type of reaction this would be: 2KNO₃+ H₂CO₃ → K₂CO₃ + HNO₃
Answer:
It's a double displacement reaction.
Water freezing is an exothermic process? tue or false
Answer:
Explanation:
When water becomes a solid, it releases heat, warming up its surroundings. This makes freezing an exothermic reaction.
So the correct answer is True
The concentration of hydroxide ions in the antacid, milk of magnesia, is 5.3 × 10−4 M. Calculate the concentration of hydronium ions at 25°C.
Answer:
1.89 × 10^-11 M
Explanation:
Recall that;
[H^+] [OH^-] = 1 × 10^-14
[H^+] = concentration of hydronium ions
[OH^-] = concentration of hydroxide ion
Where [OH^-] = 5.3 × 10−4 M
[H^+]= 1 × 10^-14/5.3 × 10−4
[H^+]= 1.89 × 10^-11 M
Milk of magnesia, with a concentration of hydroxide ions of 5.3 × 10⁻⁴ M, has a concentration of hydronium ions of 1.9 × 10⁻¹¹ M.
Milk of magnesia (Mg(OH)₂) is an antacid, in which the concentration of hydroxide ions is 5.3 × 10⁻⁴ M.
We can calculate the concentration of hydronium ions at 25°C using the following expression.
[tex][H_3O^{+} ][OH^{-} ] = Kw = 1.0 \times 10^{-14} \\\\[H_3O^{+} ] = \frac{1.0 \times 10^{-14} }{[OH^{-} ]} = \frac{1.0 \times 10^{-14} }{5.3 \times 10^{-4} } = 1.9 \times 10^{-11} M[/tex]
where,
Kw is the ionic product of waterSince [H₃O⁺] < 10⁻⁷ M, the milk of magnesia is basic.
Milk of magnesia, with a concentration of hydroxide ions of 5.3 × 10⁻⁴ M, has a concentration of hydronium ions of 1.9 × 10⁻¹¹ M.
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how many moles of H2O are used to make 3.12 moles of NH3
Answer:
4.73 mol NH
Explanation:
What we're doing here is calculating basic mole-mole relationships, something that you'll be doing quite a bit!
The steps to solving mole-mole problems like this are
write the balanced chemical equation for the reaction (this is given)
divide the number of moles of the given known substance (3.55) by that substance's coefficient in the chemical equation (3)
multiply that number by the coefficient of the substance you're trying to find (4)
Using simple dimensional analysis, it looks like this:
Answer:
4.68 H2O is needed to make 3.12 moles of NH3
Explanation:
Using stoichiometry, we can convert Moles of NH3 into Moles of H20
since we're converting moles to moles, we take the given mole of NH3
3.12, and multiply it by the Mole ratio, which in this case is (H20/NH3) or (6/4)
so then: 3.12 * 6/4 = 4.68 mols of H2O
1. A potassium atom has a larger atomic radius than a sodium atom. What statement about potassium correctly explains this difference?
A) It has a larger nuclear charge
B) It has a lower electronegativity
C) It has more energy levels occupied by electrons
D) It has a lower ionization energy
2. Which of the following elements has the greatest electron affinity (largest negative value)?
A) Mg
B) Al
C) Si
D) P
E) S
3. The electron affinity of fluorine is essentially equal to
A) The negative of the ionization energy F
B) The ionization energy F-
C) The negative of the ionization energy F-
D) The ionization energy Ne
E) The negative of the ionization energy Ne
The electron affinity is the energy required to remove an electron from an atom to yield a negative ion.
We know that atomic size increases down the group as more shells are added. This is because, inter-electronic repulsion pushes the electrons in the outermost shell farther away from the nucleus. Hence potassium atom has a larger atomic radius than a sodium atom because It has more energy levels occupied by electrons.
Electron affinity increases across the period. The more nonmetallic an element is, the more negative its electron affinity. Hence, sulfur has the greatest electron affinity.
Electron affinity is the opposite of ionization energy. It therefore follows that, the electron affinity of fluorine is essentially equal to the negative of the ionization energy F.
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