Answer:
jk
Explanation:
Determine the number of electrons and protons in the following element: Tc Group of answer choices 43 protons, 43 electrons 43 protons, 56 electrons 56 protons, 43 electrons 99 protons, 43 electrons
249 g of potassium iodide, KI, is mixed with 496.5 g of lead(II) nitrate, Pb(NO3)2.
The equation of the reaction is represented below.
[Pb(NO3)2 = 331; KI = 166; PbI2 = 461, KNO3 = 101]
Calculate the number of moles of excess reagent left.
Give your answer to three significant figures.
Answer: The number of moles of excess reagent left is 0.750 moles
Explanation:
The number of moles is calculated by using the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
For KI:Given mass of [tex]KI[/tex] = 249 g
Molar mass of [tex]KI[/tex] = 166 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of KI}=\frac{249g}{166g/mol}=1.5mol[/tex]
For [tex]Pb(NO_3)_2[/tex]:Given mass of [tex]Pb(NO_3)_2[/tex] = 496.5 g
Molar mass of [tex]Pb(NO_3)_2[/tex] = 331 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of }Pb(NO_3)_2=\frac{496.5g}{331g/mol}=1.5mol[/tex]
The given chemical equation follows:
[tex]2KI+Pb(NO_3)_2\rightarrow 2KNO_3+PbI_2[/tex]
By stoichiometry of the reaction:
If 2 moles of KI reacts with 1 mole of lead(II) nitrate
So, 1.5 moles of KI will react with = [tex]\frac{1}{2}\times 1.5=0.75mol[/tex] of lead(II) nitrate
As the given amount of lead(II) nitrate is more than the required amount. Thus, it is present in excess and is considered as an excess reagent.
Thus, KI is considered a limiting reagent because it limits the formation of the product.
Moles of excess reactant ([tex]Pb(NO_3)_2[/tex]) left = [1.5 - 0.75] = 0.750 moles
Hence, the number of moles of excess reagent left is 0.750 moles
2. Which element below would be the best choice when creating a covalent molecule with an
Oxygen atom?
A. Na
B. Mg
C. Ne
D. O
How does bioremediation improve the quality of life for humans?
Completely natural process with almost no harmful side effects
what's the common name for hydrogen oxide
Complete the symbol equation for the preparation of sodium sulfate
2NaOH(aq) + H2SO4(aq) => Na2SO4(s) + 2H2O(l)
This is a neutralization reaction.
S
O
sulfur dioxide
3. In liquid sulfur dioxide, which of the following types of intermolecular force(s) would be present?
London Dispersion Forces
Dipole-Dipole
II.
Hydrogen Bonding
IV
Covalent Bonds
A. I
B. I and II
C. I,II, and I
D. I, II, III, and IV
Answer:
B
Explanation:
B
You have 350 mL of 3.4 M hydrochloric acid (HCl). How many grams of HCl gas are dissolved? Bonus: what is the volume of the HCl at STP?
Answer:
1. 43.44g of HCl
2. 26.67 L of HCl
Explanation:
1) Molarity of a solution = number of moles (n) ÷ Volume (V)
According to the provided information in this question,
V = 350 mL = 350/1000 = 0.350L
Molarity = 3.4 M
Using Molarity = n/V
3.4 = n/0.350
n = 3.4 × 0.350
n = 1.19mol
Using the formula below to calculate the mass of HCl;
mole = mass/molar mass
Molar mass of HCl = 1 + 35.5 = 36.5g/mol
mole = mass/MM
mass = 1.19 mol × 36.5g/mol
mass = 43.44g of HCl
2) At STP, HCl has a pressure of 1atm, a temperature of 273K
V = ?
n = 1.19 mol
R = 0.0821 Latm/molK
Using PV = nRT
V = nRT/P
V = 1.19 × 0.0821 × 273/1
Volume = 26.67L
How do countries with different currencies trade goods with each other?
A.
They trade actual physical products to avoid confusion over currency differences.
B.
They negotiate to determine which country's currency will be used for the whole exchange.
C.
They create a new shared currency, such as the European Union countries' euro.
D.
They use the exchange rate to convert one country's currency to another's.
Answer:
D- They use the exchange rate to convert one's Country's currency to another's
Explanation:
There are moles of Carbon if I have 2.25 x 1023 atoms of Carbon? A. 0.19 moles b. 5.38 moles c. 0.37 moles d. 2.67 moles
Answer:
c. 0.37 moles
Explanation:
To find the number of moles (n) in a certain number of atoms of a substance, we divide the number of atoms by Avogadro number (nA), which is 6.02 × 10²³ atoms.
That is,
n = number of atoms ÷ 6.02 × 10²³
According to this question, there are 2.25 x 10²³ atoms of carbon (C). The number of moles contained in this carbon is as follows:
n = 2.25 x 10²³ ÷ 6.02 × 10²³
n = 2.25/6.02 × 10 (23 - 23)
n = 0.374 × 1
n = 0.374moles
a nitrde ion has 7protons,8nutrons and 10 electrons. what is the overall change
Answer:
the overall charge on the nitride anion is
( 3 − ) .
N power 3 − → the nitride anion
What are the chemical names of these compounds?
KF:
Mg3N2:
Answer:
Magnesium nitride
Explanation:
Answer:
The name of compound 'KF' is, Potassium fluoride.
The name of compound 'Mg₃N₂' is, Magnesium nitride.
Explanation:
Ionic compound : It is defined as the compound which is formed when electron gets transferred from one atom to another atom.
Ionic compound are usually formed when a metal reacts with a non-metal.
The nomenclature of ionic compounds is given by:
1. Positive ion is written first.
2. The negative ion is written next and a suffix is added at the end of the negative ion. The suffix written is '-ide'.
3. In case of transition metals, the oxidation state are written in roman numerals in bracket in-front of positive ions.
(a) KF
KF is an ionic compound because potassium element is a metal and fluorine element is a non-metal. The bond formed between a metal and a non-metal is always ionic in nature.
Thus, the name of compound 'KF' is, Potassium fluoride.
(b) Mg₃N₂
Mg₃N₂ is an ionic compound because magnesium element is a metal and nitrogen element is a non-metal. The bond formed between a metal and a non-metal is always ionic in nature.
Thus, the name of compound 'Mg₃N₂' is, Magnesium nitride.
Explain why a mixture of copper (Il) Oxide and Magnesium reacts while there is no reaction when a mixture of Copper and Magnesium Oxide is heated.
Answer:
Copper oxide + magnesium = copper + magnesium oxide
Explanation:
When copper oxide is heated with magnesium powder, then magnesium oxide and copper are formed.. For example, magnesium is more reactive than copper. ... brown copper coats the surface of the magnesium.
the volume of vessel is 6 litres. convert it into ml
Answer:
6000 ml
Explanation:
1 liter is a 1000 ml
Who can answer these?
When hydrogen sulfide gas is bubbled into a solution of sodium hydroxide, the reaction forms sodium sulfide and water. How many grams of sodium sulfide are formed of 2.68 g. of hydrogen sulfide is bubbled into a solution containing 0.0823 g. of sodium hydroxide, assuming that the limiting reagent is completely consumed
Answer:
0.0803g of Na2S are produced
Explanation:
Hydrogen sulfide, H2S, reacts with sodium hydroxide, NaOH, to produce sodium sulfide, Na2S and water.
2NaOH + H2S → 2H2O + Na2S
To solve this question we must find the moles of each reactant. With the chemical quation we can find the limiting reactant. With limiting reactant we can find the moles of Na2S and its mass
Moles NaOH -Molar mass: 40g/mol-
0.0823g * (1mol / 40g) = 0.002058moles
Moles H2S -Molar mass: 34.082g/mol-
2.68g * (1mol / 34.082g) = 0.0786 moles
For a complete reaction of 0.0786 moles of H2S are needed:
0.0786 moles H2S * (2mol NaOH / 1mol H2S) = 0.157 moles NaOH
As there are just 0.002058 moles, NaOH is limiting reactant.
The moles of Na2S produced are:
0.002058moles NaOH * (1mol Na2S / 2mol NaOH) = 0.001029 moles Na2S
Mass Na2S -Molar mass: 78.0452g/mol-
0.001029 moles Na2S * (78.0452g / mol) =
0.0803g of Na2S are producedLime is added to a lake to neutralize the effects of acid rain. The pH value of the
lake water rises from 4 to 7. What is the change in concentration of H+ ions in the
lake water?
Answer:
The change in concentration of H+ ions is -9.99×10⁻⁵
Explanation:
When pH rises, we talk about neutralization and, there is a decline in proton's concentration.
pH lower than 7 is acid
pH higher than 7 is basic
Protons are neutralized by hydroxides to make water as this:
H₃O⁺ + OH⁻ ⇄ H₂O
pH = - log [H₃O⁺]
[H₃O⁺] = 10^-pH
In conclussion: [H₃O⁺]₁ = 10⁻⁴ → 1×10⁻⁴
[H₃O⁺]₂ = 10⁻⁷ → 1×10⁻⁷
1×10⁻⁷- 1×10⁻⁴
The change in concentration of H+ ions is -9.99×10⁻⁵
Which substance is an electrolyte?
A)
C2H5OH(C)
B)
NaOH(s)
C)
H2(g)
D)
C6H1206 (s)
Answer:
B)NaOH(s)
Explanation:
co2(g)+H20+148Kcal---->H2Co3 Endotérmica o exotérmica
endothermic
requires energy to occure
explain how ships made of steel float on water
Answer:
The air that is inside a ship is much less dense than water. That's what keeps it floating
Which type of bond is found in an alkane?
O A. Double only
B. Single and double
O C. Single only
O D. Single and triple
Considering the definition of alkanes, single bonds are found in an alkane.
Definition of AlkanesAlkanes are a class of hydrocarbons (compounds containing only carbon and hydrogen) that are made up of a variable number of carbon atoms joined together by single bonds. In turn, each carbon atom bonds to hydrogen atoms, which may eventually be replaced by other atoms or functional groups.
In other words, alkanes are open or closed chain molecules that are linked by simple bonds.
Alkanes are saturated hydrocarbons because the bonds between carbon atoms are simple and stable. And as mentioned, the hydrogen atoms bonded to each carbon atom can be replaced by other atoms, such as halogens (fluorine, bromine, chlorine) or various groups or “radicals”. In the latter case, the structure becomes more complex giving rise to branched alkanes.
SummaryIn summary, single bonds are found in an alkane.
Learn more about alkanes:
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Answer: C) single only
Explanation:
just got it right
Question
Calculate the total energy, in kilojoules, that is needed to turn a 35 g block
of ice at -10 degrees C into water vapor at 100 degrees C.
Answer:
34545 J
Explanation:
Applying,
E = mc'+cm(t₂-t₁)+Cm(t₂-t₀).............. Equation 1
Where E = Total energy, m = mass of the ice, c' = latent heat of ice, c = specific heat capacity of ice, t₂ = final temperature, t₁ = initial temperature, C = specific heat capacity of water, t₀ = temperature of ice at 0°C
From the question,
Given: m = 35 g = 0.035 kg, t₁ = -10°C, t₂ = 100°C, t₀ = 0°C
Constant: C = 4200 J/kg.K, c = 2100 J/kg.K, c' = 336000 J/kg
Susbtitute these values into equation 1
E = [336000(0.035)]+[0.035×2100(100+10)]+[4200×0.035(100-0)]
E = 11760+8085+14700
E = 34545 J
Which of the following most likely happens when the volume of a gas increases the number of collisions of gas particles remains same. The number of collisions of gas particles increases. The pressure of the gas remains the same. The pressure of the gas decreases
Answer:
D. The pressure of the gas decreases!
Explanation:
According to Boyle's Law, there is an inverse relationship between the volume of a gas and its pressure!
So, if the volume of a gas increases, its pressure will decrease; the same thing will happen if the pressure of the gas increases -- the volume will decrease!
↑P↓V and ↓P↑V <---- this is what it would look like visually!!
Hope this helps! :)
When the volume of a gas increases then the pressure of the gas decreases.
What is ideal gas equation?Ideal gas equation is a hypothesis which tells about the behavior of gas in different conditions and it will be represented as:
PV = nRT
From this equation it is clear that pressure and volume are inversely proportional to each other:
P ∝ 1/V
Means if pressure increases ten volume decreases or if pressure decreases then volume increases.
Hence option (4) is correct.
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Magnesium is added to dilute hydrochloric acid. This makes bubbles of hydrogen and a colorless solution of magnesium chloride. Write down the name of one of the products of this reaction.
Answer:
The products are already in the question Hydrogen gas and Magnesium Chloride
Explanation:
2Mg +2HCl₂ = 2MgCl₂ + H₂ balanced equation if you need it
When any metal react with acid then salt and hydrogen gas is formed. Hydrogen gas and Magnesium Chloride are formed when Magnesium is added to dilute hydrochloric acid.
What is chemical reaction?Chemical reaction is a process in which two or more than two molecules collide in right orientation and energy to form a new chemical compound. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, double displacement reaction.
The products are Hydrogen gas and Magnesium Chloride. The balanced equation can be written as
Mg +2HCl[tex]\rightarrow[/tex] MgCl₂ + H₂
This makes bubbles of hydrogen and a colorless solution of magnesium chloride.
Therefore Hydrogen gas and Magnesium Chloride are formed when Magnesium is added to dilute hydrochloric acid.
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The fat adipose cells is broken down into fatty acids. Which pathway is involved in this process?
Answer:
the anwer is glycolysis
What is the cathode in an electrochemical cell?
Answer:
d but I may be wrong
Explanation:
Answer: C. The electrode where reduction occurs.
Make a flow chart on uses of metals and non metals
you have to make flow chart with explanation
Answer:
Metals:
1. Metals are strong than non metals
2. Metals can be formed in wires, thin sheets, utensils and any other heavy meachinary for industries.
3. Metals are used for building construction and used in many other manufacturers
Non Metals:
1. Non metals are less stronger than metals.
2. Non metals can be used for manufacturing bottles, toys, bags, files etc.
3. Non metals are used in making of bottles, jars, chairs etc.
Thank you.....
Have a good day.....
NEED HELP ASAP PLEASE
Identify the type of bonding, covalent, ionic, or metallic, between
the atoms in an oxygen molecule.
Answer:
here hope it helps
Explanation:
covalent bonds
On a hot summer day, a piece of ice is removed from a cooler and placed in a cup that is sitting on a picnic table. Which of the following statements are true about what happens to the ice and the cup overtime? Choose the two that apply. *
1 point
a. Heat moves from the ice to the cup.
b. The particles in the ice start to move faster.
c. Both the ice and the cup change state.
d. The cup changes temperature.
the PH of a solution with a [H+] of 1x10^9 is ?
Answer:
9
Explanation:
pH = -log[H+] = -log(1x10^9) = 9