Answer:
An ion found in some compounds used as antiperspirants contains 13 protons and 10 electrons. What is its symbol?
Solution
Because the number of protons remains unchanged when an atom forms an ion, the atomic number of the element must be 13. Knowing this lets us use the periodic table to identify the element as Al (aluminum). The Al atom has lost three electrons and thus has three more positive charges (13) than it has electrons (10). This is the aluminum cation, Al3+.
What is the empirical formula for a compound if a 2.50g sample contains 0.900g of calcium and 1.60g
of chlorine? (3pts]
Answer:
CaCl₂
Explanation:
First we convert the given masses of elements into moles, using their respective molar masses:
0.900 g Ca ÷ 40 g/mol = 0.0225 mol Ca1.60 g Cl ÷ 35.45 g/mol = 0.045 mol ClNow we divide those numbers of moles by the lowest value among them:
0.0225 mol Ca / 0.0225 mol = 10.045 mol Cl / 0.0225 mol = 2Meaning the empirical formula for the compound is CaCl₂.
HOW MANY MOLES OF CS2 FORMS WHEN 2.7 MOLE C REACTS
Select the correct answer.
What quantity might be measured in units of kilograms?
A.
the brightness of a candle
B.
the volume of a bottle
C.
the mass of a marble
D.
the electric current in a wire
Answer:
The mass of a marble.
Explanation:
Units of the other answers:
A: Light - Lumen (lm)
B: Volume - cm^3
D: Electric current - Ampere
Below is a list of the first 10 residues of the B helix in myoglobin from different organisms.
Position 1 2 3 4 5 6 7 8 9 10
Human D I P G H G Q E V L
Chicken D I A G H G H E V L
Alligator K L P E H G H E V I
Turtle D L S A H G Q E V I
Tuna D Y T T M G G L V L
Carp D F E G T G G E V L
Based on this information, which positions (a) appear unable to tolerate substitutions, (b) can tolerate conservative substitution, and (c) are highly variable?
Answer:
i dont knoiwxplanation:
A sample of polonium-210 has an initial mass of 390 milligrams (mg). If the half-life of polonium-210 is 36 days, how many mg of the sample remains after 72 days?
A.
392 mg
B.
195 mg
C.
97.5 mg
D.
48.75 mg
Answer: D. 48.75
Explanation: just took the test
Answer:
D
Explanation:
I got this question right on my test.
how real gases differ from ideal gases?
An ideal gas is one that follows the gas laws at all conditions of temperature and pressure. To do so, the gas would need to completely abide by the kinetic-molecular theory. On the other hand, a real gas is a gas that does not behave according to the assumptions of the kinetic-molecular theory.
Furthermore, the particles of an ideal gas are extremely small and have a mass equivalent to practically zero. Ideal gas particles also have no volume.
An example of a real gas is helium, oxygen, and nitrogen.
Carbon-11 decays by position emission.The nuclide formed product is
Answer:
They demonstrated that carbon-11 decays by positron emission to the stable nuclide 11B [Eq. (1)].
CH4 +2H2S = CS2+ 4H2
If the reaction shifts to the right what are the products?
If the reaction shifts to the right, which chemicals decrease in The process?
If the reaction shifts to the left what are the products?
If the reaction shifts to the left, which chemicals decrease in the process?
At a certain temperature the rate of this reaction is first order in HI with a rate constant of 0.0632 s
2HI g = H2 g + I2 g
Suppose a vessel contains HI at a concentration of 1.28M. Calculate how long it takes for the concentration of HI to decrease to 17.0% of its initial value.
Answer:
[tex]28.037\ \text{s}[/tex]
Explanation:
[tex][A]_0[/tex] = Initial concentration = 1.28 M
[tex][A][/tex] = Final concentration = [tex]0.17[A]_0[/tex]
k = Rate constant = 0.0632 s
t = Time taken
For first order reaction we have the relation
[tex]kt=\ln\dfrac{[A]_0}{[A]}\\\Rightarrow t=\dfrac{\ln\dfrac{[A]_0}{[A]}}{k}\\\Rightarrow t=\dfrac{\ln\dfrac{[A]_0}{0.17[A]_0}}{0.0632}\\\Rightarrow t=28.037\ \text{s}[/tex]
Time taken to reach the required concentration would be [tex]28.037\ \text{s}[/tex].
A compound containing phosphorus and oxygen has a molar mass of 157.9 g/mol and an empirical formula of PO3 .
Answer: The molecular formula of the compound is [tex]P_2O_6[/tex]
Explanation:
The molecular formula is the chemical formula that tells about the number of atoms of each element present in a compound. Molecular formula and empirical formula can also be the same when the number of atoms is in the simplest whole-number ratio.
To calculate the molecular formula, the number of atoms of the empirical formula is multiplied by a factor known as valency that is represented by the symbol, 'n'.
[tex]n=\frac{\text{Molecular mass}}{\text{Empirical mass}}[/tex] ...(1)
Given empirical formula is [tex]PO_3[/tex]
Empirical mass = [tex][(1\times 30.97) + (3\times 15.99)]=78.94 g/mol[/tex]
Molecular mass = 157.9 g/mol
Plugging values in equation 1:
[tex]n=\frac{157.9 g/mol}{78.94g/mol}\\\\n=2[/tex]
Molecular formula of the compound becomes [tex]P_{2\times 1}O_{2\times 3}=P_2O_6[/tex]
Hence, the molecular formula of the compound is [tex]P_2O_6[/tex]
A sample of polonium-210 has an initial mass of 390 milligrams (mg). If the half-life of polonium-210 is 36 days, how many mg of the sample remains after 36 days?
A.
48.75 mg
B.
392 mg
C.
97.5 mg
D.
195 mg
Answer:
d
Explanation:
A 35 Liter tank of Oxygen is at 315 K with an internal pressure of 190 atmospheres. How many moles of gas does the tank contain?
which solution has a higher percent ionization of the acid , a .10 M solution of HC2H3O2 (aw) or a .010 M solution of HC2H3O2(aq)
Answer:
0.0010 M of HC2H302(aq)
Mechanical digestion begins in the_____ and involves physical processes, such as chewing.
Answer:
begins in the mouth
PLEASE HELP ME classify this reaction:
your options are
1. synthesis
2. decomposition
3. combustion
4. single replacement
5. double replacement
explain your answer for brainliest
But Are Punnett square percentages always correct?
Answer:
yes
Explanation:
cuz is a square and if all angles are equal of a square then it is correct
What mass of iron(III) oxide will be formed if 9.30 L of oxygen at STP react with excess iron?
Answer:
12
Explanation:
because that plot and the iron
I need the correct answers
Answer:
Acids: Tastes Sour
Has a ph less than 7
Base: Bitter
Has a ph greater than 7
slippery
Acid&Base: Conducts electricity
Based on the molar masses. how can you tell that an equation is balanced
Which statement best defines the term innate behavior?
behavior that is taught through watching others
behavior that is simple, untaught, and born knowing
behavior that is taught through both good and bad experiences
behavior that is untaught but very complex
Answer: behavior that is simple, untaught, and born knowing
Have a nice dam day!!
The term that describes innate behavior is:
D. behavior that is untaught but very complex
What does innate behavior stand for?Intr-insic or "intuitive" ways of behaving are innate and don't need learning or related knowledge to be performed. Models incorporate romance and ways of behaving, departure and guarded moves, and hostility. Movement and Migration Innate or ins-tinctual behaviors rely on response to sti-muli.
Thus, option D is correct.
Find more information about Innate behavior here:
brainly.com/question/14311636
A 25.0 mL NaOH solution of unknown concentration was titrated with a 0.189 M HCl solution. 19.6 mL HCl was required to reach the equivalence point. In a separate titration, a 10.0 mL H3PO4 solution was titrated with the same NaOH solution. This time, 34.9 mL NaOH was required to reach the equivalence point. What is the concentration of the H3PO4 solution
Answer:
0.172 M
Explanation:
The reaction for the first titration is:
HCl + NaOH → NaCl + H₂OFirst we calculate how many HCl moles reacted, using the given concentration and volume:
19.6 mL * 0.189 M = 3.704 mmol HClAs one HCl mol reacts with one NaOH mol, there are 3.704 NaOH mmoles in 25.0 mL of solution. With that in mind we determine the NaOH solution concentration:
3.704 mmol / 25.0 mL = 0.148 MAs for the second titration:
H₃PO₄ + 3NaOH → Na₃PO₄ + 3H₂OWe determine how many NaOH moles reacted:
34.9 mL * 0.148 M = 5.165 mmol NaOHThen we convert NaOH moles into H₃PO₄ moles, using the stoichiometric coefficients:
5.165 mmol NaOH * [tex]\frac{1mmolH_3PO_4}{3mmolNaOH}[/tex] = 1.722 mmol H₃PO₄Finally we determine the H₃PO₄ solution concentration:
1.722 mmol / 10.0 mL = 0.172 MThe more energy that particles have, the ___ they move.
The more energy that particles have, the more they move.
Calculate the specific heat capacity for bone based on the above data. Show your work.
Answer:
What above data?
Explanation:
There is no data to be seen here.
If 1.00 g of KCl is completely dissolved in 24.5 g of water, what is the percent composition (by mass) of the solution that is formed?
Answer:
3.92%
Explanation:
The solution that is formed is of KCl in water. This means that the percent composition by mass is given by the formula:
Mass of KCl / Mass of Solution * 100%We now calculate the mass of solution:
Mass of Solution = Mass of KCl + Mass of Water = 1.00 g + 24.5 gMass of Solution = 25.5 gFinally we calculate the percent composition:
1.00 g / 25.5 g * 100% = 3.92%In both industry and research there are often times when one particular component of a mixture needs to be separated from a solution. Maybe it is a rare metal that is dissolved in a mixture of minerals. Maybe it is a particular protein from lysed plant cells. If the desired component is volatile, distillation could be used. But if the goal is to separate ions in solution, fractional precipitation is preferred.
a. True
b. False
Answer:
a. True
Explanation:
Distillation process is a process that is used to separate the components or the substances from the liquid mixtures by using selectively boiling and condensation.
While fractional precipitation is a process which separates the ions from solution based on the different solubilities.
Therefore, the answer is true.
16. Given the unbalanced equation:
_Al + CuSO4 → _A1,(SO2), + --Cu
When the equation is balanced using
the smallest whole-number coefficients,
what is the coefficient of AI?
(1) 1 (2) 2 (3) 3
(4) 4
Explanation:
Consider matrix A.
What is the inverse of A? Fill in the missing elements in the matrixs.Consider matrix A.
What is the inverse of A? Fill in the missing elements in the matrixs.
(2) 2.
Explanation:
2Al + 3CuSO4 → Al2(SO4)3 + 3Cu
Hence, now yet it's balanced chemical equation.
What is the total number of Joules lost when 10. grams of water at 80.°C is cooled to 60.°C?
Answer:
[tex]\boxed {\boxed {\sf 836.8 \ Joules \ lost}}[/tex]
Explanation:
Since we are given the mass and change in temperature, we should use the following formula for heat.
[tex]q= mc \Delta T[/tex]
In this formula, m is the mass, c is the specific heat capacity, and ΔT is the change in temperature.
We know the mass of the water is 10 grams. We will have to look up water's specific heat, because it is not given. It is 4.184 J/g °C.
Let's find the change in temperature. This is the difference of the final and initial temperature. The water started at 80 °C and cooled to 60°C.
ΔT= final temperature - initial temperature ΔT= 60° C - 80°C ΔT= -20 °CNow we have values for each variable.
m= 10 gc= 4.184 J/g°C ΔT= -20°CSubstitute the values into the formula.
[tex]q= 10 \ g * 4.184 \ J/g \textdegree C * -20 \textdegree C[/tex]
Multiply the first 2 numbers. The units of grams will cancel each other out.
[tex]q= 41.84 \ J/ \textdegree C * -20 \textdegree C[/tex]
Multiply again. This time, the degrees Celsius cancel.
[tex]q= -836.8 \ J[/tex]
A total of 836.8 Joules are lost.
What is the most likely meaning of concentration in paragraph 7?thinking thinking about about one one thing thing in in a a focused focused waywayamount amount of of a a substance substance found found in in waterwaterarea area where where something something comes comes fromfromchance chance to to be be foundfound
Answer:
amount of a substance found in water.
Answer:
amount of a substance found in water.
Explanation:
name the process which takes place when propene gas molecules are converted into a giant molecule
Answer:
Polymerization, any process in which relatively small molecules, called monomers, combine chemically to produce a very large chainlike or network molecule, called a polymer. The monomer molecules may be all alike, or they may represent two, three, or more different compounds.
If 36.0 g of NaOH (MM = 40.00 g/mol) are added to a 500.0 mL volumetric flask, and water is added to fill the flask, what is the concentration of NaOH in the resulting solution
Answer:
Molarity of NaOH = 1.8 M.
Explanation:
From the question given above, the following data were obtained:
Mass of NaOH = 36 g
Molar mass of NaOH = 40 g/mol
Volume = 500 mL
Molarity of NaOH =?
Next, we shall determine the number of mole in 36 g of NaOH. This can be obtained as follow:
Mass of NaOH = 36 g
Molar mass of NaOH = 40 g/mol
Mole of NaOH =?
Mole = mass / molar mass
Mole of NaOH = 36 / 40
Mole of NaOH = 0.9 mole
Next, we shall convert 500 mL to L. This can be obtained as follow:
1000 mL = 1 L
Therefore,
500 mL = 500 mL × 1 L / 1000 mL
500 mL = 0.5 L
Finally, we shall determine the molarity of NaOH. This can be obtained as follow:
Mole of NaOH = 0.9 mole
Volume = 0.5 L
Molarity of NaOH =?
Molarity = mole / Volume
Molarity of NaOH = 0.9 / 0.5
Molarity of NaOH = 1.8 M
