Answer:
6
Explanation:
6, because the number after decimals are considered significant but the 0 after the last number is not significant.
A reaction requires 22.4 L of gas at STP . There are 25.0 L of gas at 101.5 kPa and 373 K.
Which statement is true?
Use the ideal gas law: PV = nRT where R = 8.31 L-kPa/mol-K
A. There is not enough gas for the reaction.
B. Given this information, there is no way to tell if there is enough gas for the reaction.
C. There is excess gas for the reaction.
D. There is enough gas for the reaction.
Answer:
STP is 101.325 kPa pressure and 273K temperature
Also, at STP, 1 mol of an ideal gas = 22.4 L
Since the question states that 22.4 L are needed at STP, we know that ONE MOLE is needed. Now, the question is, how many moles are actually present?
V = 25.0 L
P = 101.5 kPa
T = 373K
n = ?
R = 8.31 L-kPa/Kmol
Solving the ideal gas law for n (moles) and comparing that to 1 mole, we have...
n = PV/RT = (101.5)(25.0)/(8.31)(373)
n = 0.82 moles of gas. THIS IS NOT ENOUGH as it is less than the ONE mole required.
Explanation:
Beryllium is in Group 2.
What does this tell you about the electronic structure of beryllium?
Answer:
[He] 2s²
Explanation:
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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HELP ;-;
Vanillin, C8H8O3, the principal component of vanilla beans, is very similar to glucose, C6H12O6 a type of sugar. Brittany Spears has a life threatening allergy to vanillin. After one of her concerts she was found dead in her dressing room. A glass lined with a white powder was found smashed on the floor next to her. Police think the glass was lined with vanillin suggesting she was murdered. A 2.54 g sample of this powder underwent carbon-hydrogen analysis. It’s combustion was found to produce 5.875 g of CO2 (g) and 2.41 g of H2O(g) . Find the empirical formula of this compound and determine if Brittany may have been poisoned?
b) Is this evidence enough to conclude for certain that the identity of the powder on the glass is indeed vanillin? Why or why not?
Answer:
The empirical formula is: CH2
Th powder is not vainillin
Explanation:
We can find empirical formula of a compound CₐHₓOₙ knowing that moles CO2 = Moles C, 2 Moles H2O = Moles H and that we can find the mass of oxygen by the difference of masses of the atoms:
Moles C = Moles CO2 -Molar mass: 44.01g/mol-
5.875g * (1mol/44.01g) = 0.1335 moles C * (12.01g/mol) = 1.60gC
Moles H2O and moles H -Molar mass: 18.01g/mol-
2.41g H2O * (1mol / 18.01g) = 0.1339 moles H2O * (2mol H / 1mol H2O) =
0.2676 moles H * (1g/mol) = 0.27g H
The empirical formula of this compound is the ratio of C:H:
0.2676 moles H / 0.1335 moles C = 2
The empirical formula is:
CH2
In vainillin, the moles of Carbon = Moles of Hydrogen. the experiment shows the moles of hydrogen are twice the moles of carbon. Thus, the powder is not vainillin
What is created when electrons become detached from their local atom?'
a) An Atom
b) Cation
c) Anion
d) Delocalized electrons
Answer:
B. Cation
Explanation:
As an electron is removed from the atom it is then converted into a positively charged ion known as a Cation.
Hope this helps u
A student is provided with a sample of iron pyrite and a sample of gold. Suggest how the student could distinguish between the two substances
Answer:
Gold and pyrite both have a brilliant metallic luster, but are different tones of yellow. Gold is golden to silvery yellow, whereas pyrite is a pale to medium brassy yellow that sometimes tarnishes.
Explanation:
Para la siguiente reacción: 2NH 3(g) + CO 2(g) ———> (NH 2 ) 2 CO (l) + H 2 O (l) a) ¿Cuántos gramos de NH 3 se necesitan para formar 720 g de (NH 2 ) 2 CO? b) ¿Cuántos moléculas de agua se obtienen a partir de 9 litros de CO 2 ayudenme porfa
Answer:
a. 408g de NH3 son necesarios
b. 2.42x10²³ moléculas de agua se obtienen
Explanation:
a. Basados en la reacción, 2 moles de NH3 producen una mol de (NH2)2CO. Para resolver esta pregunta debemos convertir la masa de (NH2)2CO a moles. Estas moles a moles de NH3 y su respectiva masa:
Moles (NH2)2CO -Masa molar: 60.06g/mol-
720g * (1mol / 60.06g) = 11.99 moles (NH2)2CO
Moles NH3:
11.99 moles (NH2)2CO * (2mol NH3 / 1mol (NH2)2CO) = 23.98 moles NH3
Masa NH3 -17.031g/mol-:
23.98 moles NH3 * (17.031g / mol) = 408g de NH3 son necesarios
b. 1mol de CO2 produce 1mol de agua. Se debe convertir el volumen a moles usando PV = nRT. Estas moles = Moles de agua. 1mol = 6.022x10²³ moléculas:
Asumiendo STP:
PV = nRT; PV / RT = n
Donde P = 1atm a STP
V = 9L
R = 0.082atmL/molK
T = 273.15K a STP
1atm*9L / 0.082atmL/molK*273.15K = n
n = 0.402 moles CO2 = Moles H2O
Moléculas:
0.402 moles agua * (6.022x10²³ moléculas / 1mol) =
2.42x10²³ moléculas de agua se obtienenIf you have 3 moles of a gas at a pressure of 2.5 atm and a volume of 8 liters, what is the temperature?
a. 57.86 K
b. 0.81 K
c. 25 K
d. 81.26 K
Answer:
d
Explanation:
pv=nrt
2.5×1.01×10^5×8×10^-3=3×8.31×T
T=
The value of the temperature can be determined by ideal gas law and the temperature will be 0.81 K.
What is temperature ?The average kinetic energy of particular atoms and molecules in a system is measured by the temperature.
What is ideal gas Law?
Ideal gas law explain the relationship between pressure. temperature and volume.
Ideal gas law can be expressed as, PV=nRT.
where, P is pressure. V is volume , n is number of moles ,R is gas constant and T is temperature. It is given that, n= 3 mole, P = 2.5 atm, V = 8 L, T=?, R = 8.31.
Calculation of temperature by using ideal gas law is shown as:
Now, put the values of given data in ideal gas law equation.
T = PV/nR
=2.5×8/3×8.32
= 0.81 K
Therefore, the temperature will be 0.81K.
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Please somone help me with a chemistry question brainliest to whoever answers correctly and 20 points
Answer:
3132 is the answer
Explanation:
3BaCl2 + Al2S3 → 3BaS + 2AlCl3
Answer:
Explanation:
Hope this helps u !!
In explosive combustion the rapid expansion of --------------- causes explosion and the production of ------------------
Answer:
Volume; high temperature and pressure
Explanation:
In an explosive combustion the rapid expansion of the volume causes explosion and the production of high temperature and pressure.
The substance is usually in a confined place and the expansion usually reaches a breaking point in which it is expelled from the space usually accompanied with a loud noise and high amount of temperature and pressure change thereby releasing its gas constituents.
What species is reduced in the reaction below?
Zn° + 2 Ag+ → Zn2+ + 2 Agº?
A) Znº
B) Agº
C) Zn2+
D) Ag+
Answer: The correct option is D) [tex]Ag^+[/tex]
Explanation:
The oxidation reaction is defined as the reaction in which a chemical species loses electrons in a chemical reaction. It occurs when oxidation number of a species increases.
A reduction reaction is defined as the reaction in which a chemical species gains electrons in a chemical reaction. It occurs when oxidation number of a species decreases.
For the given chemical reaction:
[tex]Zn^0+2Ag^+\rightarrow Zn^{2+}+2Ag^0[/tex]
On the reactant side:
Oxidation number of Zn = 0
Oxidation number of Ag = +1
On the product side:
Oxidation number of Zn = +2
Oxidation number of Ag = 0
As the oxidation number of Ag is decreasing from +1 to 0. Thus, [tex]Ag^+[/tex] is getting reduced.
Hence, the correct option is D) [tex]Ag^+[/tex]
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.
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Answer: C) single only
Explanation:
just got it right
Question 12 of 15
Matter can undergo chemical reactions and nuclear reactions. Which
statement is true for both types of reactions?
A. The reactants are changed to form the products.
B. The reactants can be elements or compounds.
C. The products can be elements or compounds.
D. The products can be the same as the reactants.
Answer:
A. The reactants are changed to form the products.
Explanation:
Chemical reactions are reactions that involves a change in the chemical composition of substances involved while a nuclear reaction is the process of fusing together or splitting the nucleus of an atom. According to this question, matter is said to undergo both types of reaction.
However, one similarity in both chemical and nuclear reactions is that substances called REACTANTS are changed to form PRODUCTS. In nuclear reaction, the atoms joined or split are the reactants while the ones formed are the products.
Answer: A
Explanation:
How does anatomy provide evidence for evolution?
I'll give brainlist!! Simple answer please.
Suppose that you want to make 12 g of lithium oxide.
What are the minimum masses of lithium and oxygen you will need?
A. Li= 5.6 g O2= 6.4 g
B. Li 6.5 g O2= 4.6 g
C. Li= 0.6 g O2 46.4 g
D. Li= 15.6 g O2 6.4 g
Answer:
A. Li= 5.6 g O2= 6.4 g
Explanation:
Lithium oxide, Li2O, is an oxide that contains 2 moles of Li and 1 mole of O per mole of oxide. To solve this question we must find the mass of each atom in the molecule as follows:
2Li = 2*6.941g/mol = 13.882g/mol
O = 1*16g/mol = 16g/mol
Molar mass Li2O:
16+13.882 = 29.882g/mol
The mass of lithium is:
12g * (13.882g/mol / 29.882g/mol) = 5.6g Li
And the mass of oxygen:
12g * (16g/mol / 29.882g/mol) = 6.4g O
Right answer is:
A. Li= 5.6 g O2= 6.4 gHELP PLEASEEEEE HURRY!!
Answer:
The answer is c
A circuit is set up with two parallel resistors, each of a resistance of 250Ω.
b. If another resistor of resistance 300Ω is added in series with these two parallel resistors, what is the total
resistance?
c. If a voltage of 120V is put across the circuit in b, what will the current be in the circuit?
Answer:
425 and 0.28A
Explanation:
Resistance for resistors in parallel
1/ R = 1/250 +1/250
=0.008
R = 1/ 0.008 = 125
Total resistance
R= 125+ 300
=425
...
V= IR
I= V/R
I = 120/425
= 0.28 A
Calculate the volume of this regular solid.
What is the volume of the rectangular prism?
1
6 cm
5 cm
9 cm
The atoms of elements A (blue) and B (orange) form 2 compounds shown here. Do these compounds obey the law of multiple proportions?
Hello. You have not presented the image that presents the two elements mentioned in the question. This makes it impossible for your question to be answered. However, I will try to help you as best I can.
To say whether the compounds obey the law of multiple proportions, you should observe whether one of the elements, formed from the compounds, maintains a fixed mass, while the other element presents the mass in a varied amount of small, whole numbers, spread across the formed compounds .
This is because the law of multiple proportions states that an element must have a fixed mass when reacting with another element to create compounds. This reaction will allow this element to keep the mass fixed, while the other element will generate different compounds, where each one presents a part of the mass of the forming element, in small and whole numbers.
Cells can regulate different processes in two ways. They can turn on and off the genes that make enzymes, or they can
A)
increase the activation energy of a reaction.
B)
increase the amount of energy needed to carry out the preferred process.
C)
regulate the enzymes that are already made.
D)
decrease the amount of energy needed to carry out the preferred process.
calculate the pressure in atm of .68 mol of H at 298K and occupying 4.5 L
Answer:
3.7 atm
General Formulas and Concepts:
Atomic Structure
MolesGas Laws
Ideal Gas Law: PV = nRT
P is pressureV is volumen is number of molesR is gas constantT is temperatureExplanation:
Step 1: Define
Identify variables
[Given] n = 0.68 mol H
[Given] T = 298 K
[Given] V = 4.5 L
[Given] R = 0.0821 L · atm · mol⁻¹ · K⁻¹
[Solve] P
Step 2: Find Pressure
Substitute in variables [Ideal Gas Law]: P(4.5 L) = (0.68 mol)(0.0821 L · atm · mol⁻¹ · K⁻¹)(298 K)Multiply [Cancel out units]: P(4.5 L) = (0.055828 L · atm · K⁻¹)(298 K)Multiply [Cancel out units]: P(4.5 L) = 16.6367 L · atmIsolate P [Cancel out units]: P = 3.69705 atmStep 3: Check
Follow sig fig rules and round. We are given 2 sig figs as our lowest.
3.69705 atm ≈ 3.7 atm
What is stoichiometry?
Answer:
hope it help u !!!!
Explanation:
Stoichiometry is the relationship between the relative quantities of substances taking part in a reaction or forming a compound, typically a ratio of whole integers
How many moles are in 2.11 x 1014 molecules of LiBr?
Answer: There are [tex]12.71 \times 10^{-9}[/tex] moles present in [tex]2.11 \times 10^{14}[/tex] molecules of LiBr.
Explanation:
According to the mole concept, there are [tex]6.022 \times 10^{23}[/tex] molecules present in 1 mole of a substance.
Hence, moles in [tex]2.11 \times 10^{14}[/tex] molecules of LiBr are calculated as follows.
[tex]Moles = \frac{2.11 \times 10^{14}}{6.022 \times 10^{23}}\\= 12.71 \times 10^{-9}[/tex]
Thus, we can conclude that there are [tex]12.71 \times 10^{-9}[/tex] moles present in [tex]2.11 \times 10^{14}[/tex] molecules of LiBr.
Using the periodic table, choose the more reactive nonmetal.
Br or As
Reactivity of non-metals depend on their ability to gain electrons. So, smaller is the size of a non-metal more readily it will attract electrons because then nucleus will be more closer to valence shell. ... Hence, Br is the non-metal which will be more reactive than At.
Answer:
br is more reactive than as
what happened to the ionization energy of hydrogen"H" when its electron affinity
Fossil fuels are considered to be:
a.
irreplaceable resources
c.
renewable resources
b.
nonrenewable resources
d.
hazardous wastes
Please select the best answer from the choices provided
A
B
C
D
Question: (02.01 MC) Which state of matter does this image represent?
O Solid
O Liquid
O Gas
O Plasma
The table shows the specific heat of four substances—brick, dry soil, paper, and water. If all four substances were exposed to sunlight for the same amount of time, which substance would heat up the fastest?
Answer:
Brick
Explanation:
.................
how many grams are represented by 1.45 moles of Koh? Determine your answer to the correct number of significant figures.
Answer:
[tex]\boxed {\boxed {\sf 81.4 \ g\ KOH}}[/tex]
Explanation:
We are asked to convert 1.45 moles of potassium hydroxide (KOH) to grams.
1. Molar MassThe molar mass is the mass in grams of 1 mole of a substance. The values are found on the Periodic Table. They are the same as the atomic masses but the units are grams per mole (g/mol) instead of atomic mass units (amu).
We have the compound KOH. Look up the molar masses of the individual elements.
Potassium (K): 39.098 g/mol Oxygen (O): 15.999 g/mol Hydrogen (H): 1.008 g/molThe formula for the compound has no subscripts, so there is 1 mole of each element in 1 mole of the compound. We can simply add the molar masses.
KOH: 39.098 + 15.999 + 1.008 =56.105 g/mol2. Convert Moles to GramsBased on the molar mass, there are 56.105 grams of KOH in 1 mole. Create a ratio using this information.
[tex]\frac {56.105 \ g\ KOH}{ 1 \ mol \ KOH}[/tex]
We are converting 1.45 moles of KOH to grams, so we multiply by this value.
[tex]1.45 \ mol \ KOH *\frac {56.105 \ g\ KOH}{ 1 \ mol \ KOH}[/tex]
The units of moles of KOH cancel.
[tex]1.45\ *\frac {56.105 \ g\ KOH}{ 1 }[/tex]
[tex]81.35225 \ g\ KOH[/tex]
3. RoundThe original measurement of moles has 3 significant figures, so our answer must have the same.
For the number we calculated, that is the tenths place. The 5 in the hundredths place (81.35225) tells us to round the 3 up to a 4.
[tex]81.4 \ g\ KOH[/tex]
Approximately 81.4 grams of potassium hydroxide are represented by 1.45 moles.
The ideal gas law equation is: PV = nRT
Use the ideal gas law to calculate the moles of gas in a container that has a pressure
of 700kpa, volume of 2L and a temperature of 450K.
Answer:
The answer is the first option 0.37 moles
Explanation:
the ideal gas law is PV = nRT, so in the terms of n,
n = PV/RT (divide both sides by RT to let n stand alone)
given: P = 700 kpa, V = 2L, T = 450 K , R = 8.31
n = (700 * 2) / (8.31 * 450)
= 1400/3739.5
= 0.34
