We can change the substance chemically by
freezing it.
True or false
Which best explains why aluminum is a nonrenewable resource?
A)It cannot be quickly replaced.
B)It is expensive to process.
C)It conducts electricity.
D)It is useful to humans.
Answer:
A.) It cannot be quickly replaced.
Explanation:
Aluminum is extremely useful to humans but is semi-difficult to produce. Because of this, your answer will be numero uno. (Or A.)
Help me with homework.
The chemical equation is said to be balanced if the number of atoms in the reactants and products is the same
Further explanationEquation balanced ⇒ total number of atoms in reactants(on the left)= total number of atoms in products(on the right)
H₂+O₂---> H₂O
Reactants : H₂, O₂
Products : H₂O
not balanced
H₂O₂ ---> H₂O+O₂
Reactants : H₂O₂
Products : H₂O, O₂
not balanced
Na+O₂ ---> Na₂O
Reactants : Na, O₂
Products : Na₂O
not balanced
N₂+H₂ ---> NH₃
Reactants : N₂, H₂
Products : NH₃
not balanced
P₄+O₂---> P₄O₁₀
Reactants : P₄, O₂
Products : P₄O₁₀
not balanced
Fe+H₂O ----> Fe₃O₄ + H₂
Reactants : Fe, H₂O
Products : Fe₃O₄
not balanced
Hannah added a silvery white metal to a beaker of cold water and noticed that
gas bubbles were given off and a different substance formed. When she
repeated the activity with hot water she noticed the gas bubbles were released
much more rapidly. Which statement best explains why the reaction occurred
faster in hot water?
A ) Hot water increases the collision rate of the molecules, causing the
reaction to occur faster.
B ) Hot water changes the concentration of the chemicals, causing the
reaction to occur faster.
C ) Hot water increases the surface area of the molecules, causing the reaction
to occur faster.
D ) Hot water changes the chemical composition of the water molecules,
causing the reaction to occur faster.
Answer:
A. Hot water increases the collision rate of the molecules, causing the
reaction to occur faster.
Explanation:
Hot water molecules move faster than cold water molecules.
What’s the answer????
Answer:
Greater
Greater
Explanation:
The amplitude of a wave is the height of the wave or the vertical displacement of the wave motion. We determine a wave amplitude usually by looking at the graph of the wave.
Amplitude is directly proportional to the energy of a wave. The higher the amplitude of a wave, the more its energy.
Frequency is the number of waves that passes a point at a particular instance of time. It is also directly proportional to the energy carried by a wave. The higher the frequency of a wave, the greater its energy.
someone help me please i’ll give brainly
Answer:
b
Explanation:
i looked it up on Google
P and Q are two substances such that the melting point of P and the boiling point of Q are the same. If P is a solid at a certain temperature, what state will Q be in at the same temperature?
Answer:
Explanation:
Firstly, it should be noted that melting and freezing points are the same. Thus, when a substance melts at a certain temperature, it means it can also start freezing/solidifying at that same temperature. That been said, when the substance P is a solid at a certain temperature, the other compound Q will boil at that same temperature and hence will be a gas at that same temperature.
If P is solid, it simply means that Q must still be in the liquid state.
From the question, we can see that, the melting point of P and the boiling point of Q are the same. The melting point of a substance is the temperature at which the solid turns to liquid while the boiling point of a substance is the temperature at which a liquid turns to a gas.
If P is solid, it simply means that Q must still be in the liquid state. It has not yet started boiling since the melting point of P and the boiling point of Q are the same.
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A sample of CO2 weighing 86.34g contains how many molecules?
Answer:
1.181 × 10²⁴ molecules CO₂
General Formulas and Concepts:
Chemistry - Atomic Structure
Reading a Periodic TableUsing Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Explanation:
Step 1: Define
86.34 g CO₂
Step 2: Identify Conversion
Avogadro's Number
Molar Mass of C - 12.01 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of CO₂ - 12.01 + 2(16.00) = 44.01 g/mol
Step 3: Convert
[tex]86.34 \ g \ CO_2(\frac{1 \ mol \ CO_2}{44.01 \ g \ CO_2} )(\frac{6.022 \cdot 10^{23} \ molecules \ CO_2}{1 \ mol \ CO_2} )[/tex] = 1.18141 × 10²⁴ molecules CO₂
Step 4: Check
We are given 4 sig figs. Follow sig fig rules and round.
1.18141 × 10²⁴ molecules CO₂ ≈ 1.181 × 10²⁴ molecules CO₂
Can someone help? Ill give brainliest!
Directions: count each side of the reaction then Circle yes or no if it follows the law of conservation of mass
Answer:
Explanation:
before the reaction you have K=2 and Cl=4
after the reaction K=2 and Cl=2 so it does not follow the law of conservation
Which of the following most likely happens when thermal energy is removed from a chemical reaction?
Answer:
fewer collisions occur between particles or lowering the temperature
Explanation:
What is the total number of grams of a 32-gram sample of 32P remaining after 71.5 days of decay?
Answer:
1 g
Explanation:
The following data were obtained from the question:
Original amount (N₀) = 32 g
Time (t) = 71.5 days
Half-life of phosphorus (t½) = 14.3 days
Amount remaining (N) =?
Next, we shall determine the rate of disintegration. This can be obtained as follow:
Half-life of phosphorus (t½) = 14.3 days
Decay constant (K) =?
K = 0.693 / t½
K = 0.693 / 14.3
K = 0.0485 /day
Finally, we shall determine the amount remaining as illustrated below:
Original amount (N₀) = 32 g
Time (t) = 71.5 days
Decay constant (K) = 0.0485 /day
Amount remaining (N) =?
Log (N₀/N) = Kt/2.303
Log (32/N) = 0.0485 × 71.5 / 2.303
Log (32/N) = 3.46775 / 2.303
Log (32/N) = 1.5058
Take the antilog of 1.5058
32/N = antilog (1.5058)
32/N = 32.05
Cross multiply
32 = N × 32.05
Divide both side by 32.05
N = 32 / 32.05
N = 0.998 ≈ 1 g
Thus, the amount remaining after 71.5 days is approximately 1 g.
The half-life of a radioactive substance refers to the time taken for the substance to Decay to half of its initial size. Hence, the mass of the substance left after 71.5 days is 1 gram.
Initial mass = 32 g Half life = 14.3 daysAfter 14.3 days ;
32 / 2 = 16 gramsAfter 14.3 × 2 = 28.6 days :
16/2 = 8 gramsAfter 14.3 × 3 days = 42.9 days :
8 / 2 = 4 gramsAfter 14.3 × 4 days = 57.2 days :
4 /2 = 2 gramsAfter 14.3 × 5 days = 71.5 days :
2 /2 = 1 gram.Hence, the mass of the sample left after 71.5 days would be 1 gram.
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If, in the reaction below, 49 grams of Fe3O4 produces a 78.25% yield of Fe. How many grams are produced?
Really need help on this please, I’ll give brainliest!!
explain why the reaction between lead (II) nitrate and concentrated sulphuric (VI) acid starts and stops immediately?
Answer:
The reaction produces insoluble lead (II) sulphate which coats the surface of lead (II) nitrate [Pb(NO3)]
A car is traveling at 50mph. How long will it take the car to travel 300 miles?
Answer:
6 hours
Explanation:
If it is traveling at 50mph and needs to reah 300 miles, to figure this problem out you would want to divide 300 by 50 to get 6 hours. So it will take six hours until the car travels 300 miles
Hope this helps.
Answer: A car travels at a rate of 50 miles per hour. how long will it take the car to travel 300 miles?
Explanation: .
Applying the distance formula:
d = rt
where
d is distance (300 miles)
r is rate (50 mph)
t is time (hours)
.
300 = 30t
300/30 = t
10 hours = t
The electronegativity values of carbon, hydrogen, and nitrogen are compared in the table.
Comparison of
Electronegativity
Element Electronegativity
Carbon
2.5
Hydrogen 2.1
Nitrogen 3.0
Which of the following statements is true about the strength of the intermolecular forces in CH4 and NH3? (4 points)
Answer:
C. CH₄ is less than NH₃ because the NH bond is more polar than the CH bond
Explanation:
The intermolecular forces between ammonia is far stronger than for methane. Between the molecules of ammonia we have the presence of hydrogen bonds. This bond is absent in methane.
Hydrogen bonds are one of the strongest intermolecular forces. It is as a result of the electrostatic attraction between the hydrogen atom of one molecule and the electronegative atom N, O and F of another molecule.
This strong interaction is absent in methane which has just dipole - dipole attraction.The strength of the hydrogen bond depends on the electronegativity of the combining atoms.
Which of the following is an indication of a physical change?
O A. The formation of a new substance
O B. Giving off a smell
O C. A change in the shape of a substance
O D. The production of gas and heat
Answer:
A change in the shape of a substance
Explanation:
Because when ths shape of a sunstance changes , its physical appearance changes .A physical change is a change to the physical—as opposed to chemical—properties of a substance. They are usually reversible. The physical properties of a substance include such characteristics as shape (volume and size), color, texture, flexibility, density, and mass.
Help please! A gas occupies 500 mL at 270 mm Hg and 55°C. If the pressure is changed to 1.8 atm and the temperature is
increased to 100°C, what is the new volume? Be sure to show the setup and the final answer and unit.
Show Your Work
Answer:
V₂ = 112.14 mL
Explanation:
Given data:
Initial volume = 500 mL
Initial pressure = 270 mmHg (270/760 =0.355 atm)
Initial temperature = 55 °C (55 +273 = 328 K)
Final temperature = 100°C (100+273 = 373 K)
Final volume = ?
Final pressure = 1.8 atm
Formula:
P₁V₁/T₁ = P₂V₂/T₂
P₁ = Initial pressure
V₁ = Initial volume
T₁ = Initial temperature
P₂ = Final pressure
V₂ = Final volume
T₂ = Final temperature
Solution:
V₂ = P₁V₁ T₂/ T₁ P₂
V₂ = 0.355 atm × 500mL × 373 K / 328 K × 1.8 atm
V₂ = 66207.5 atm .mL. K / 590.4 K.atm
V₂ = 112.14 mL
A helium balloon in a closed car occupies a volume of 1.32 L at 30.0°C. If the car is parked on a hot day and the volume of the balloon increases to 2.50 L what is the temperature in the car, assuming the pressure remains constant?
Answer:
T₂ = 573.86 K
Explanation:
Given data:
Initial volume = 1.32 L
Initial temperature = 30.0°C (30+273 = 303 K)
Final volume = 2.50 L
Final temperature in car = ?
Solution:
Solution:
The given problem will be solve through the Charles Law.
According to this law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.
Mathematical expression:
V₁/T₁ = V₂/T₂
V₁ = Initial volume
T₁ = Initial temperature
V₂ = Final volume
T₂ = Final temperature
Now we will put the values in formula.
V₁/T₁ = V₂/T₂
T₂ = V₂T₁/V₁
T₂ = 2.50 L × 303 K / 1.32 L
T₂ = 757.5 L.K / 1.32 L
T₂ = 573.86 K
Give two examples of compounds exhibiting double covalent bonds between atoms of its constituent molecules and explain why they form a double covalent bond.
Answer: Due to the sharing of electrons, they exhibit characteristic physical properties that ... Here, we discuss two classes of compounds based on the bond type that ... Covalent bonds are characterized by the sharing of electrons between two or ... Describe the types of orbital overlap that occur in single, double, and triple bonds
Explanation: That's what I think it is.
what is the element for I am a metal and I have 6 Neutrons. PLEASE ANSWER TO MY QUESTION QUICKLY!!!!
Answer:
carbon-12
Explanation:
carbon 6/12 isotope has 6 neutrones and it is considered as a metal.
When 0.25 moles of NH3 are produced according to the reaction below, how many moles of H2 must have reacted?
N2 + 3 H2 --> 2 NH3
O 1.5 moles H2
O 0.38 moles H2
O 0.25 moles H2
O 0.17 moles H2
Answer:
Explanation:
by stoichiometry
nNH3/2=nH2/3
0.25/2=nH2/3
nH2=0.25×3/2
nH2=0.375 mol
so its 0.38 mol
Answer:
I have this quiz rn I will try 0.38 if it is right I’ll edit this and say that
Explanation:
What product(s) are formed during this chemical reaction? (There will be two correct answers)
Ca + Na3PO3 rightwards arrow
CaNaPO3
Ca3(PO4)2
Ca2(PO4)3
Ca(PO3)2
Na
Na3
CaNa
No Reaction
Answer:
Ca3(PO4)2 and Na
Explanation:
The reaction equation is;
3Ca + 2Na3PO3 -------> Ca3(PO3)2 + 6Na
We must remember that calcium is above sodium in the electrochemical series. This implies that calcium can displace sodium from its solution. Calcium has a reduction potential of -2.87 V while sodium has a reduction potential of -2.71 V. The ion with the more negative reduction potential can easily displace the other in aqueous solution.
This explains why the reaction above is possible.
Write a BALANCED chemical equation for the acid base reaction between aqueous perchloric acid and aqueous calcium hydroxide.
Answer:
2HClO4 + Ca(OH)2 = Ca(ClO4)2 + 2H2O
Explanation:
Formula for aqueous perchloric acid is; HClO_4 (aq)
Formula for aqueous calcium hydroxide is; Ca(OH)_2 (aq)
Thus chemical equation is;
HClO4 + Ca(OH)2 = Ca(ClO4)2 + H2O
We have to balance it and so we now have;
2HClO4 + Ca(OH)2 = Ca(ClO4)2 + 2H2O
As the frequency decreases the wavelength...
Answer:
Increase
Explanation:
Assuming a sinusoidal wave moving at a fixed wave speed, wavelength is inversely proportional to frequency of the wave: waves with higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths.
Construct the chemical formulas for the ionic compounds.
Ionic compounds are formed from metal and non-metal elements
Further explanationThe chemical formula of compounds (especially ionic compounds) can be determined from the charge of each ion.
Determination of the ionic charge of the constituent elements of the compound can be seen from the electron configuration to achieve stability according to the octet rule
The charge of each ion will be crossed in the compound
Aluminum bromide
Al³⁺ + Br⁻ ⇒ AlBr₃
Magnesium bromide
Mg²⁺ + Br⁻ ⇒ MgBr₂
Sodium sulfide
Na⁺ + S²⁻ ⇒ Na₂S
Sodium nitride
Na⁺ + N³⁻ ⇒ Na₃N
01:44:12
Considering the temperature vs. time graph below, how does the temperature at the beginning of a change of state
compare with the temperature at the end of the change?
Temperature vs. Time
140
4
100
80
Temperature (°C)
3
30
40
20
2
0
20
Time (min)
The temperature is always lower
The temperature is always the same
The temperature is usually lower
The temperature is usually higher
Air that has been removed from a bell jar will NOT allow _____________ waves to travel through the jar. Question 4 options: sound light water
Answer:
Sound.
Explanation:
Sound requires a medium such as air to travel.
How many moles of Cl2 are needed in order to produce 100.0 grams of FeCl3 given the following
equation: 2 Fe + 3 Cl2 → 2 FeCl3
B
T
Answer:
0.92moles
Explanation:
Given reaction:
2Fe + 3Cl₂ → 2FeCl₃
Mass of FeCl₃ = 100g
Unknown:
Number of moles of Cl₂ needed = ?
Solution:
To solve this problem, we work from the known specie to the unknown.
From the mass of the FeCl₃ given, we can solve for the number of moles of the unknown.
Number of moles of FeCl₃;Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of FeCl₃ = 56 + 3(35.5) = 162.5g/mol
Number of moles = [tex]\frac{100}{162.5}[/tex] = 0.62mole
From the reaction expression;
2 mole of FeCl₃ is produced from 3 moles of Cl₂
0.62 mole of FeCl₃ will be produced from [tex]\frac{0.62 x 3}{2}[/tex] = 0.92mole
The number of moles of Cl₂ = 0.92moles
An independent variable is....
A: What we measure
B: What we change
C: What stays the same
D: What we conclude
Answer:
B - What we change
Explanation:
Dependent Variable - What we measure
Control Variable - what stays the same
Conclusion - what we conclude
Hope this can Help!
:D
1. Find the number of protons, neutrons, electrons and electronic structure of flourine 919F.
2. Write the chemical formula of following compound.
Magnesium hydroxide
3. Balance the following equation
_H2 + _O2 --------> __H2O
1. ₉¹⁹F
2. Mg(OH)₂
3. 2H₂ + O₂ ⇒ 2H₂O
Further explanation1. Fluorine, atomic number : 9 , mass number = 19
Symbol : ₉¹⁹F
protons=electrons=atomic number = 9
neutrons = mass number - atomic mass
[tex]\tt n=19-9=10[/tex]
Configuration : [He] 2s² 2p⁵
2. Magnesium hydroxide is an ionic compound and is a strong base consisting of 2 ions:
Positive ion: Magnesium: Mg²⁺
negative ion: Hydroxide: OH⁻
The charges of the two are crossed, so that the compound becomes:
Mg(OH)₂
3. Reaction :
H₂ + O₂ --------> H₂O
give coefficient :
aH₂ + bO₂ --------> H₂O
H, left = 2a, right 2⇒2a=2⇒a=1
O, left = 2b, right 1⇒2b=1⇒b=0.5
Reaction becomes :
H₂ + 0.5O₂ --------> H₂O x 2
2H₂ + O₂ --------> 2H₂O