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+.
ii) Sodium thiosulphate dissolves in dilute nitric acid at a steady rate. Copy out which
of the following changes would quicken up the reaction- 3
a. Cooling the reacting vessel to drop the temperature.
b. Breaking the reactants into smaller pieces.
c. Adding more concentrated acid.
d. Using more sodium thiosulphate.
Answer:
d
Explanation:
what is the chemical equation for aq nitrate ion reacts with s arsenic trihydride and produces s arsenic and g ammonia?
Answer:
Explanation:
At a pressure of 1 atm, the temperature 115.9 K is called the fill in the blank 1 of Kr . The normal boiling point for Kr is at K The triple point pressure for Kr is atm The critical pressure for Kr is 54.3 atm. At temperatures above 209.4 K and pressures above 54.3 atm, Kr is a _________ . Kr is a _________ at 50.3 atm and 105 K. Kr is a _________ at 0.720 atm and 131 K. Kr is a _________ at 1.00 atm and 118 K.
Answer:
melting point, 119.8 K, 0.72 atm, supercritical fluid, solid, gas, liquid.
Explanation:
Let's refer to the phase diagram (not to scale) for krypton.
At a pressure of 1 atm, the temperature 115.9 K is called the melting point of Kr, and it is the temperature at which it passes from solid to liquid.
The normal boiling point for Kr is at 119.8 K, which is, at 1 atm, the limit between the liquid and the gas state.
The triple point pressure for Kr is 0.72 atm, as can be seen in point C.
The critical pressure for Kr is 54.3 atm.
At temperatures above 209.4 K and pressures above 54.3 atm, Kr is a supercritical fluid, according to the region it is in the phase diagram.
Kr is a solid at 50.3 atm and 105 K, according to the region it is in the phase diagram.
Kr is a gas at 0.720 atm and 131 K, according to the region it is in the phase diagram.
Kr is a liquid at 1.00 atm and 118 K, according to the region it is in the phase diagram.
What is the difference between how a mercury barometer and an aneroid barometer measure air pressure?
Answer:
Aneroid barometer and mercury barometer are such two types. The main difference between aneroid and mercury barometer is that aneroid barometer measures the atmospheric pressure using the expansion of a metal whereas mercury barometer measures the atmospheric pressure by adjusting the height of mercury inside a tube.
Explanation:
Write out and balance the chemical equation:
A solution of nickel (II) chloride reacts with a solution of potassium hydroxide
to produce solid nickel (II) hydroxide and a solution of potassium chloride.
Explanation:
NiCl2 + KOH = NiOH + KCl
since nickel is the primary element in nickel ii chloride, find the oxidation no of nickel in the compound and chlorine should have 2 as a subscription since the ii in the compound represents that nickel has an oxidation no of 2
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.
[H3O+] = 2.9 x 10-10 M
ph level
Answer:
9.54
Explanation:
Fr the question given above, the following data were:
Concentration of hydronium ion [H3O⁺] = 2.9x10¯¹⁰ M
pH =?
The pH of the solution can be obtained as follow:
pH = –Log [H3O⁺]
pH = –Log 2.9x10¯¹⁰
pH = 9.54
Thus, the pH level of the solution is 9.54
Calculate the value of Delta H for the reaction CaCO3 --> CO2 + CaO from the following enthalpy changes:
Ca + C + 3/2 O2 --> CaCO3 ΔH = -1206.9 kJ
Ca + ½ O2 --> CaO ΔH = -635.1 kJ
C + O2 -->CO2 ΔH= - 393.5 kJ
Explanation:
crescents discuss wentz eg
Answer:
2,2,1,2
2 Ca + 2 CO2 + 1 O2 → 2 CaCO3
Explanation:
Got it right on Oddesyware!!!!
What is the pOH for a solution whose pH is 2?
Answer:
12
Explanation:
Because it is pH and pOH, you can use the relationship of 14-pH=pOH, or 14-pOH=pH. Using this you should get the pOH to be 12.
Which of the two Lewis/electron dot structure representations, which is
the correct one for oxygen gas? PICTURE BELOW
Answer:
A
Explanation:
What is true of an earthquake that causes major damage to buildings in an area?
It has a high magnitude.
It has a high frequency.
It has a low frequency.
It has a low magnitude.
The correct option is :
=》It has a high magnitude.
the damage caused by an earthquake is proportional to its magnitude, as much the magnitude is, that much damage will be caused by it.
The term used to indicate and earthquake that causes major damage to buildings in an area is called a high magnitude earthquake. Hence, option a is correct.
What is high magnitude earthquake?The most typical way to gauge an earthquake's size is by its magnitude. No matter where you are or how violent the shaking is, it is the same number since it represents the size of the earthquake's source.
The USGS no longer uses the outmoded Richter scale to determine the magnitude of major, teleseismic earthquakes. Several magnitude scales measure various aspects of the earthquake, but the Richter scale measures the biggest wobble (amplitude) on the recording.
Currently, the USGS uses the Moment Magnitude scale to report earthquake magnitudes, however many different magnitudes can be calculated for comparison and research. Therefore, option a is correct.
Find more on earthquakes:
https://brainly.com/question/29500066
#SPJ3
Genes influence an organism's traits by coding for:
A
Cells
Answer:
First, the protein may be a structural protein, contributing to the physical properties of cells or organisms. ... Second, the protein may be an enzyme that catalyzes one of the chemical reactions of the cell. Therefore, by coding for proteins, genes determine two important facets of biological structure and function.
Explanation:
i think it will help you
What is the oxidation state of S in S2O32−?
A. +3 B. +2 C. –2 D. +4
Answer:
it'd be +2
Explanation:
Since 3 atoms of oxygen are present, so its combined oxidation number will be3(−2)=−6. Now this ion contains a charge of−2, where the sum of the oxidation number of all atoms in an atom is equal to−2. So the oxidation number of S in S2O2−3 should be +2.
What is the name for the compound with a chemical formula B6Si.
The chemical formula B₆Si belongs to the compound silicon hexaboride.
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.
Excessive use of chemical fertilizer causes chemical pollution.how?
Answer:
Chemical fertilizers contain various chemicals that cause harm to soil and water.
Explanation:
Chemical fertilizers contain various chemicals such as phosphates, nitrates which can cause water pollution. Eutrophication caused by the environmental nitrogen and phosphorous that causes rich minerals and chemicals in the water.
These can cause excessive growth of the algae and phytoplankton that will cause depletion of the oxygen from the water body and organisms will die due to this.
Consider the oxidation of sodium metal to sodium oxide described by the balanced equation:
4 Na + O2 → 2 Na2O. What is the theoretical yield of Na2O in grams from 9.0 mol of O2?
show steps
Answer:
1116 g.
Explanation:
The balanced equation for the reaction is given below:
4Na + O₂ —> 2Na₂O
From the balanced equation above,
1 mole of O₂ reacted to produce 2 moles of Na₂O.
Next, we shall determine the theoretical yield of Na₂O. This can be obtained as follow:
From the balanced equation above,
1 mole of O₂ reacted to produce 2 moles of Na₂O.
Therefore, 9 moles of O₂ will react to produce = 9 × 2 = 18 moles of Na₂O.
Finally, we shall determine the mass in 18 moles of Na₂O. This can be obtained as follow:
Mole of Na₂O = 18 moles
Molar mass of Na₂O = (23×2) + 16
= 46 + 16
= 62 g/mol
Mass of Na₂O =?
Mass = mole × molar mass
Mass of Na₂O = 18 × 62
Mass of Na₂O = 1116 g
Thus, the theoretical yield of Na₂O is 1116 g.
_____ is the process of linking smaller molecules to form long chains of higher molecular weight.
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
The half-life for a 400-gram sample of radioactive element X is 3 days. How much of element X remains after 15 days have passed?
A.
12.5 g
B.
25 g
C.
50 g
D.
100 g
Answer:
The correct answer is - A. 12.5 gram.
Explanation:
Given:
The initial amount of sample = 400 gram
the half-life cycle = 3 days
after 15 days remain value = ?
Solution:
The number of half-lives in 15 days = 15/3
= 5 half-lives
the remaining amount of sample after one half-life 3 days = 400/2 = 200
the remaining amount of sample after 2nd half-life or 6 days= 200/2 = 100
the remaining amount of sample after 3rd half-life or 9 days= 100/2 = 50
the remaining amount of sample after 4th half-life or 12 days= 50/2 = 25
the remaining amount of sample after 5th half-life or 15 days= 25/2 = 12.5 gram
Thus, the correct answer is = 12.5 g.
In a reaction, the actual yield is always at least as large as the theoretical yield.
True or false.
give short explanation on answer
Think about the decomposition reaction of ozone.
2 O3 ----> 3 O2
If 71.7 mol ozone are in this reaction, what is the theoretical yield of O2 (in gram)?
Answer:
3441.6 grams.
Explanation:
2 O₃ → 3 O₂
First we convert 71.7 moles of ozone (O₃) into moles of oxygen gas (O₂), using the stoichiometric coefficients of the reation:
71.7 mol O₃ * [tex]\frac{3molO_2}{2molO_3}[/tex] = 107.55 mol O₂
Then we convert 107.55 moles of O₂ into grams, using the molar mass of O₂:
107.55 mol * 32 g/mol = 3441.6 g
the amount of thermal energy stored in an object depends on what
Answer:
The amount of thermal energy stored in an object depends on three things.
The mass of the object.The temperature of the object. The amount of energy that the particular material stores per degree of temperature.What happens when earth rotates on its axis and how long take?
Answer:
We get Day and Night... It takes 24 hours for the earth to rotate on its axis
How many kilojoules of energy are required to heat 50.0 g of ethyl alcohol from 60.0 °C to 78.4 °C and vaporize it? The specific heat of ethyl alcohol is 2.138 J/g°C; heat of vaporization is 853 J/g.
Answer:
44.62 kJ
Explanation:
Firstly, we calculate the energy needed to heat the liquid (ethyl alcohol) by using the formula:
Q = m × c × ∆T
Where;
Q = Amount of heat (J)
m = mass (g)
c = specific heat of ethyl alcohol = 2.138 J/g°C
∆T = change in temperature (°C)
According to the information given in this question;
Q = ?, m = 50.0g, ∆T = (78.4°C - 60°C) = 18.4°C
Therefore, using Q = mc∆T
Q = 50 × 2.138 × 18.4
Q (amount of energy needed to heat ethyl alcohol) = 1966.96 J
Next, we calculate and add the amount of heat needed to vaporize by using the formula;
How many kilojoules of energy are required to heat 50.0 g of ethyl alcohol from 60.0 °C to 78.4 °C and vaporize it? The specific heat of ethyl alcohol is heat of vaporization is 853 J/g.
How many moles are in 9.83 x 1021 atoms of Na
Answer:
0.016 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
We have
[tex]n = \frac{9.83 \times {10}^{21} }{6.02 \times {10}^{23} } \\ = 0.01632...[/tex]
We have the final answer as
0.016 molesHope this helps you
Becky wants to model an ecosystem. Which of the following modeling tools would best help her illustrate an ecosystem?
A.
a rubber ball
B.
a terrarium
C.
a map
D.
a set of building blocks
Answer:
c
Explanation:
Which statement best explains the genetic variation that results from sexual
reproduction?
A. Each chromosome contains many different genes.
B. Offspring receive a mix of genes from two different parents.
c. Offspring receive genes that are exactly the same as one parent's
genes.
O D. Each chromosome contains many copies of the same gene.
Answer:
Each chromosome contains many copies of the same gene
Answer:
Offspring receive a mix of genes from two different parents
Good luck!
How many liters of solvent are are required to make a 5.34 M solution using 12.52
mol of solute?
How many grams of N2 is needed to produce 2000 grams NH3?
Answer:
1644 g
Explanation:
Step 1: Write the balanced equation
N₂ + 3 H₂ ⇒ 2 NH₃
Step 2: Calculate the moles corresponding to 2000 g of NH₃
The molar mass of NH₃ is 17.03 g/mol.
2000 g × 1 mol/17.03 g = 117.4 mol
Step 3: Calculate the moles of N₂ needed to produce 117.4 moles of NH₃
The molar ratio of N₂ to NH₃ is 1:2. The moles of N₂ needed are 1/2 × 117.4 mol = 58.70 mol
Step 4: Calculate the mass corresponding to 58.70 moles of N₂
The molar mass of N₂ is 28.01 g/mol.
58.70 mol × 28.01 g/mol = 1644 g