Answer: Results will tell you which hypothesis is true.
Explanation: The hypothesis becomes a theory if the results support it. d.A new experiment is designed to provide additional data about the hypothesis. Imagine that a team of scientists test a certain hypothesis, and the experimental results show that it is false. ... The results will show which other hypotheses must be true.
Consider a monoprotic weak acid ( HAHA ) that is titrated with a strong base. What is the relationship between the strength of the weak acid and the pH of the solution at the equivalence point?A. There is no relationship between the strength of the acid and the pH at the equivalence point. B. The pH at the equivalence point is always 7 in an acid base titration. C. The weaker the acid, the higher the pH at the equivalence point. D. The stronger the acid, the higher the pH at the equivalence point.
Answer:
C. The weaker the acid, the higher the pH at the equivalence point.
Explanation:
In a titration, a solution which concentration is known is added gradually to another solution of unknown concentration, until the chemical reaction between the two solutions is complete.
The pH in the equivalence point is equal to 7.00 only if both the acid and base are strong. When one or both reactants are weak, the pH in the equivalence point is not equal to 7.00.
In the equivalence point, the amount of strong base (like NaOH) added is just enough to react stoichiometrically with the weak acid. The resulting solution "only" contains the conjugated base A⁻. A solution of Na⁺A⁻ is the solution of a weak base:
A⁻ + H₂O ⇄ HA + OH⁻ Kb=Kw/Ka
In the equivalence point of the titration of a weak base with a strong base, the pH is higher than 7.00 because at this point the acid is transformed into its conjugate base.
An Sulfur tetrafluoride gas is collected at 23.0 °C in an evacuated flask with a measured volume of 20.0 L. When all the gas has been collected, the pressure in the flask is measured to be 0.230 atm . Calculate the mass and number of moles of sulfur tetrafluoride gas that were collected. Be sure your answer has the correct number of significant digits. mass: 1 g N10 mole: mol X & ? Explanation Check
mass = 20.48 g
moles=0.1895
Further explanationIn general, the gas equation can be written
Pv=nRTwhere
P = pressure, atm
V = volume, liter
n = number of moles
R = gas constant = 0.08205 L.atm / mol K
T = temperature, Kelvin
P=0.23 atm
V=20 L
T=23+273=296 K
[tex]\tt n=\dfrac{PV}{RT}=\dfrac{0.23\times 20}{0.082\times 296}=0.1895[/tex]
mass SF₄ (MW=108,07 g/mol) :
[tex]\tt 0.1895\times 108,07 g/mol=20.48~g[/tex]
According to the following reaction, how many moles of hydrobromic acid are necessary to form 0.274 moles bromine?
hydrobromic acid (aq) —>hydrogen (g) + bromine (1)
moles hydrobromic acid
Answer:
0.548 moles of HBr are required
Explanation:
Given data:
Number of moles of hydrobromic acid = ?
Moles of bromine formed = 0.274 mol
Solution:
Chemical equation:
2HBr → H₂ + Br₂
Now we will compare the moles of HBr with Br₂.
Br₂ : HBr
1 : 2
0.274 : 2×0.274=0.548
Thus, 0.548 moles of HBr are required.
Sealed containers of fizzy drinks contain dissolved carbon dioxide. The dissolved CO2 is in equilibrium with a small quantity of gaseous CO2 at the top of the container.
Find partial pressure of CO2 gas in 355 ml can of fizzy drink at 25C if the concentration of CO2 in the fizzy drink 0.1 M. Given that Henry’s law constant for CO2 is 3.3 x 10-2 M atm-1.
What mass of CO2 is dissolved in a 355 ml can of fizzy drink when it is stored at 25C.
Answer:
3 atm
1.6 g
Explanation:
Step 1: Given data
Volume of the solution (V): 355 mLConcentration of the solution (C): 0.1 MHenry’s law constant for CO₂ (k): 3.3 × 10⁻² M atm⁻¹.Step 2: Find partial pressure (P) of CO₂ gas
We will use Henry's law.
C = k × P
P = C / k
P = 0.1 M / 3.3 × 10⁻² M atm⁻¹
P = 3 atm
Step 3: Calculate the mass of CO₂ gas
The molar mass of carbon dioxide is 44.01 g/mol.
0.355 L × 0.1 mol/L × 44.01 g/mol = 1.6 g
which type of energy change causes a
leaf to grow
Electromagnetic energy
Explanation:
Growth is one of the characteristics of living things. It refers to the increase of an organism. A leaf is part of a plant, which is a photosynthetic organism i.e. an organism capable of producing its own food using energy from sunlight. Light energy is a part of the ELECTROMAGNETIC ENERGY.
This light energy is used to synthesize glucose (food) via photosynthesis. The glucose, which stores chemical energy in its bond is then broken down to yield ATP used for growth. Hence, the transformation of electromagnetic energy to light energy is how a leaf grow.
If 49.0 g of O2 is mixed with 49.0 g of H2 and the mixture is ignited, what is the maximum mass of water that may be produced?
Answer:
[tex]55.2gH_2O[/tex]
Explanation:
Hello!
In this case, since the reaction between hydrogen and oxygen to produce water is:
[tex]2H_2+O_2\rightarrow 2H_2O[/tex]
When equal masses of each reactant go in contact to carry out the reaction, we can identify the maximum mass of yielded water as the fewest mass yielded by each reactant, just as shown below:
[tex]m_{water}^{by\ H_2}=49.0gH_2*\frac{1molH_2}{2.02gH_2}*\frac{2molH_2O}{2molH_2}*\frac{18.02gH_2O}{1molH_2O} =170gH_2O\\\\m_{water}^{by\ O_2}=49.0gO_2*\frac{1molO_2}{32.0gO_2}*\frac{2molH_2O}{1molO_2}*\frac{18.02gH_2O}{1molH_2O} =55.2gH_2O[/tex]
Thus, since hydrogen yields more water than real, we limit the maximum mass of water to those 55.2 g yielded by oxygen as hydrogen would be in excess.
Best regards!
How does evidence of chemical
reactions indicate that new substances
with different properties are formed?
Answer:
Changes in Properties Changes in properties result when new substances form. For instance, gas production, formation of a precipitate, and a color change are all possible evidence that a chemical reaction has taken place. ... Change in Color A color change can signal that a new substance has formed.
Explanation:
The chemical reaction indicate the formation of new substance by change in nature of original compound and shows chemical changes in the reaction.
What is chemical reaction?Chemical reaction is defined as process in which two or more molecules collide with the proper orientation and enough force to produce a new product.
It is also defined as a procedure in which one or more compounds, known as reactants, are changed into one or more distinct substances, known as products.
There are mainly seven types of reaction.
Synthesis reactionDecomposition reactionDisplacement reactionDouble displacement reactionCombustion reactionRedox reactionAcid-Base reactionThus, the chemical reaction indicate the formation of new substance by change in nature of original compound and shows chemical changes in the reaction.
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How do you think energy flows in and out of the earth's atmosphere ?
The sample of 15.0 g of KCl is dissolved into a solution with a total volume of 250.0 mL. What is the molarity of KCl in the solution?
Answer:
0.805 M.
Explanation:
Hello!
In this case, since the molarity of a solution is computing by dividing the moles of solute over the volume of solution in liters (M=n/V), for 15.0 g of potassium chloride (74.55 g/mol) we compute the corresponding moles:
[tex]n=15.0gKCl*\frac{1molKCl}{74.55gKCl}=0.201molKCl[/tex]
Next, since the volume is 0.2500 in liters, the molarity turns out:
[tex]M=\frac{0.201mol}{0.2500L} \\\\M=0.805M[/tex]
Best regards!
Describe the relationship between predator and prey in a balanced ecosystem
Answer:
The predator-prey relationship helps to hold the populations of the two species in equilibrium. ... If the population of prey increases, there is more food for predators. So after a slight period, the predator population is also increasing. If the number of predators increases, more prey is captured.
Explanation:
Answer:
i eat you, you die
Explanation:
thats how life works
Help ASAP
Please and thank you
Answer: C
Explanation: Everything else is true.
Please i really need help it's due today
Answer:
there is your answer hope it helped :3
When water boils, it pushes upward against the air pressure pushing down on it. If there is less air pressure, how does that affect the pooling point ?
Calculate the amount of heat (in J) needed to raise the temperature of 3.50 g of water from 22.4oC to 98.8oC.
Answer:
76.4oC or 169.52oF
Explanation:
That's the amount of heat needed
The heat capacity is the heat amount lost or gained by the object in a thermodynamic system. The heat needed to raise the temperature of the water is 1117.7 Joules.
What is heat capacity?Heat capacity (q) is the heat an object loses or gains to alter the temperature of the thermodynamic system by a difference of a degree Celsius. The heat capacity is given by the mass, specific heat capacity, and temperature change.
Given,
Mass of water (m) = 3.50 gm
Specific heat (c) = 4.18 J/ g°C
The temperature change (∆T) = T₂ - T₁
= 98.8 °C - 22.4 °C
= 76.4 °C
The heat capacity is given as,
q = mc∆T
Substituting values above:
q = 3.50 gm × 4.18 J/ g °C × 76.4 °C
q = 1117.7 J
Therefore, 3.50 g of water has a heat capacity of 1117.7 Joules.
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What is the atomic mass of aluminum?
Help ASAP!!!! Already got a D in that class subject is science but that’s the closed I can get
Answer:
26.982
Explanation:
Use the periodic table
Helium is a....
a. metalloid
b. nonmetal
c. metal
Answer:
NonmetalExplanation:
Electric charges that are different attract each other.
True
False
Answer:
it is true bc i looked it up
Look at the picture below. Name the isotope.
Answer:
carbon-13
Explanation:
Name something that has zero thermal energy.
Answer:
When all molecules in a system stop moving completely, there is zero thermal energy
Explanation:
It is impossible to reach though
A solution containing molecular nonpolar molecules will conduct electricity
True or False?
Answer:
true
Explanation:
Is iron man made or natural
Answer:
Iron is natural. Paper is man-made
Explanation:
Answer:
iron
Explanation:
I need help, due in 30 mins
Answer:
1.Reaction rate is how fast a chemical reaction proceeds.
2.Nature of the reaction, Pressure factor
, Solvent, Catalyst and inhibitors.
3.Physical change is a temporary change. A chemical change is a permanent change. A Physical change affects only physical properties i.e. shape, size, etc.
4. One example of the effect of temperature is the use of lightsticks or glowsticks.
5.When the particle size of a fixed mass of a solid reactant becomes smaller, the total exposed surface area becomes larger, the rate of reaction increases. an example could be ice and water when the atoms are stuck together a solid but all over the place as a liquid.
6. Sometimes a reaction depends on catalysts to do their job. In that case, changing the concentration of the catalyst can speed up or slow down the reaction. For example, enzymes speed up biological reactions, and their concentration affects the rate of reaction.
7.A catalyst is a chemical substance that affects the rate of a chemical reaction by altering the activation energy required for the reaction to proceed. For example, a catalyst could cause a reaction between reactants to happen at a faster rate or at a lower temperature than would be possible without the catalyst.
Explanation:
I hope this helps have a great day! :)
What is the temperature 0 Kelvin called?
What happens at that temperature?
Answer:
0 Kelvin is called Absolute Zero. Particles will stop moving, and lose all energy.
The reaction between iron(II) oxide and carbon monoxide produces iron and carbon dioxide. How many moles of iron can be obtained when 1.50 mol FeO reacts with an excess of CO ?
FeO+CO⟶Fe+CO2
Answer:
1.5 moles of Fe produced.
Explanation:
Given data:
Moles of FeO react = 1.50 mol
Moles of iron produced = ?
Solution:
Chemical equation:
FeO + CO → Fe + CO₂
Now we will compare the moles of ironoxide with iron.
FeO : Fe
1 : 1
1.5 : 1.5
Thus from 1.5 moles of FeO 1.5 moles of Fe are produced.
1.5 moles of Fe can be obtained when 1.50 mol of FeO reacts with an excess
of CO
Moles of FeO reacted = 1.50 mol
Moles of iron produced = ? mol
The chemical equation is given as
FeO + CO → Fe + CO₂
Comparisons of FeO and Fe show they are in the ratio 1 : 1
FeO : Fe
1.5 : 1.5
which translates to the number of moles being equal
Therefore, 1.5 moles of FeO 1.5 moles of Fe are produced.
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A buffer solution is made that is 0.347 M in H2C2O4 and 0.347 M KHC2O4.
1. If Ka for H2C2O4 is 5.90E^-2, what is the pH of the buffer solution?
b. Write the net ionic equation for the reaction that occurs when 0.070 mol KOH is added to 1.00 L of the buffer solution.
Answer:
1. pH = 1.23.
2. [tex]H_2C_2O_4(aq) +OH^-(aq)\rightarrow HC_2O_4^-(aq)+H_2O(l)[/tex]
Explanation:
Hello!
1. In this case, for the ionization of H2C2O4, we can write:
[tex]H_2C_2O_4\rightleftharpoons HC_2O_4^-+H^+[/tex]
It means, that if it is forming a buffer solution with its conjugate base in the form of KHC2O4, we can compute the pH based on the Henderson-Hasselbach equation:
[tex]pH=pKa+log(\frac{[base]}{[acid]} )[/tex]
Whereas the pKa is:
[tex]pKa=-log(Ka)=-log(5.90x10^{-2})=1.23[/tex]
The concentration of the base is 0.347 M and the concentration of the acid is 0.347 M as well, as seen on the statement; thus, the pH is:
[tex]pH=1.23+log(\frac{0.347M}{0.347M} )\\\\pH=1.23+0\\\\pH=1.23[/tex]
2. Now, since the addition of KOH directly consumes 0.070 moles of acid, we can compute the remaining moles as follows:
[tex]n_{acid}=0.347mol/L*1.00L=0.347mol\\\\n_{acid}^{remaining}=0.347mol-0.070mol=0.277mol[/tex]
It means that the acid remains in excess yet more base is yielded due to the effect of the OH ions provided by the KOH; therefore, the undergone chemical reaction is:
[tex]H_2C_2O_4(aq) +OH^-(aq)\rightarrow HC_2O_4^-(aq)+H_2O(l)[/tex]
Which is also shown in net ionic notation.
Best regards!
give an example of coupling reaction
Answer:
An example is the formation of ATP, which is an endergonic process and is coupled to the dissipation of a proton gradient.
Explanation:
Hope this helped!
describe, in terms of the motion of particles in an object, how heat conduction transfers energy between objects or from one part of an object to another part at a lower temperature.
Answer:
Molecular movement
Explanation:
When an object gets hotter, its molecules gain more kinetic energy and then move faster. Therefore, the fast-moving molecules will cause those around them to move faster as well, and the colder (or more slow-moving molecule object) object or part is heated up.
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how could you tell what element it is if only a model was present?
a sample of lead had a mass of 150 g. The molar mass of lead is 207.19 g. How many moles of lead does the sample contain?
Answer:
Explanation:
no of moles=given mass/molar mass
no of moles=150 g/207.19
no of moles=0.72
We will use dimensional analysis to answer this question.
[tex]150 g * \frac{1 g}{207.19 mol} = 0.724 mol[/tex]
The answer is 0.724 mol.
an ionic bond is a force of _____between anions and ______when combined make _____compounds that are electrically_____