Answer:
54.1°C
Explanation:
Now we have the following parameters from the question;
Heat applied (H)= 18.0×10^3 Joules
Mass of the water(m)= 250g= 0.25Kg
Initial temperature of the water (θ1)= 37°C
Final temperature of the water (θ2)= the unknown
Heat capacity of water (c) = 4200JKg-1
From ;
H= mc(θ2-θ1)
Substituting values appropriately
18×10^3= 0.25 × 4200(θ2-37)
18×10^3 = 0.25 × (4200θ2 - 155400)
18×10^3 = 1050θ2 - 38850
18×10^3 + 38850 = 1050θ2
56850 = 1050θ2
θ2= 56850/1050
θ2= 54.1°C
which molecule below contains an ionic bond?
a) N2
b) CI2
c) SO2
d) KCI
17) which
of the following is a polymer?
a)starch
b)Cellulose
c)Polyvinyl chloride.
d)Sun flower.
Answer:
a b, c
Explanation:
starch is a polymer-polymeric carbohydrate
cellulose is also one-straight chain polymer
polyvinylchloride -a synthetic plastic polymer
sun flower-used for folate medication
Si una masa dada de hidrógeno ocupa 40 litros a 700 grados torr. ¿Qué volumen ocupará a 1 atmósfera de presión? (dar la presión en atmósferas). Por favor :c
Answer:
[tex]V_2=36.84L[/tex]
Explanation:
Hola,
En este caso, podemos usar la ley de Boyle, la cual nos permite analizar el comportamiento volumen-presión en un gas ideal de manera inversamente propocional:
[tex]P_1V_1=P_2V_2[/tex]
Así, dado el volumen y la presión inicial, la cual se convierte a atmósferas (760 torr = 1atm), calculamos el volumen final a 1 atm como se muestra a continuación:
[tex]V_2=\frac{P_1V_1}{P_2}=\frac{700torr*\frac{1atm}{760torr}*40l }{1atm}\\ \\V_2=36.84L[/tex]
Saludos!
Answer:
[tex]V_2=~36.84~Litros[/tex]
Explanation:
En este caso tenemos diferentes valores de volumen y presión para un primer estado:
[tex]V_1=~40~Litros[/tex]
[tex]P_1=~700~torr[/tex]
Y tenemos valores de presión para un segundo estado:
[tex]V_2=~?[/tex]
[tex]P_2=~1~atm[/tex]
Necesitamos una relación entre volumen y presión para poder hallar nuestra incognita ( [tex]V_2[/tex]). Nuestra relación es la ley de Boyle:
[tex]P_1*V_1=P_2*V_2[/tex]
Ahora bien, tenemos una unidad diferente para el presión en [tex]P_2[/tex] (atm), debemos hacer una conversión. Esta conversión puede hacerse si sabemos que 1 atm = 760 torr por lo cual [tex]P_2=760~torr[/tex]
Ahora podemos reemplazar en la ecuación:
[tex]700~torr*40~Litros=760~torr*V_2[/tex]
[tex]V_2=\frac{700~torr*40~Litros}{760~torr}[/tex]
[tex]V_2=~36.84~Litros[/tex]
El volumen sera de 36.84 Litros
Espero que ayude!
The center of the atom is known as the?
Answer:
nucleus
Explanation:
An atom itself is made up of three tiny kinds of particles called subatomic particles: protons, neutrons, and electrons. The protons and the neutrons make up the center of the atom called the nucleus and the electrons fly around above the nucleus in a small cloud.
hope that helps!
1. Which of the following is not among the first twenty elements? A. Chlorine B. Beryllium C. Iron D. Calcium 2. The number of atoms in one mole of an element is referred to as A. molecularity B. chemical symbol C. atomicity D. chemical element 3. What is the chemical symbol of Aluminum? A. AL B. Al C. aL D. al. 4. Which of the following is a heterogeneous mixture? A. Soft drink B. Air C. Flood C. Solution salt 5. Which of the following is false about mixtures? A. They can easily be separated by Chemical method B. They are not represented by chemical formula C. They can be homogenous or heterogeneous D. The constituents are physically combined 6. Which of the following elements is diatomic? A. Sodium B. Potassium C. Helium D. Oxygen 7. A diatomic element has ___________ number of atoms in one molecule of its element. A. one. B. two. C. three. D. four. 8. Which of the following is an example of a colloidal solution? A. Chalk in water B. Sand in water C. Sugar solution D. Solution of eggwhite 9. A mixture whose constituents are uniformly mixed is referred to as a A. homogeneous mixture B. suspension C. heterogeneous mixture D. colloidal solution 10. _____________ is a force that opposes motion when two surfaces are in contact with each other. A. Movement B. Pressure C. Friction D. gravity 11. _____________ is a substance, which cannot be split or broken down into any simpler form by an ordinary chemical process. A. Mixture B. Element C. Compound D. Metals. 12. Alloys are best classified as A. elements B. compounds C. mixtures D. non-metals 13. A type of force which occurs when a body moves constantly over another body is the _______ A. static force B. dynamic force C. magnetic force D. frictional force. 14. Which of the following is NOT a characteristic of friction? A. The ratio of the frictional force and the normal reaction is constant. B. The frictional force is always equal to the force applied through weight. C. Static frictional force is independent of the surface area in contact. D. Friction supports motion. 15. Use of ball or roller bearing on a turning wheel of a machine A. can cause wear and tear of the wheel B. reduces friction between the wheel and the body parts of the machine C. decreases the efficiency of the machine. D. hinders the productivity of the machine. 16. Another way of reducing friction is by A. painting B. alloying C. oiling D. braising 17. A block of wood weighs 4N lies on a horizontal table. Calculate the frictional force between the table and the wood if the coefficient of the static friction is 0.5. A. 1.0N B. 0.2N C. 2.0N D. 0.4N 18. A body of mass 2kg was moved uniformly by a force of 15N, if acceleration due to gravity is 15m/s, determine the coefficient of dynamic friction. A. 0.75 B. 1.5 C. 0.5 D. 1.75 19. The symbol for Beryllium is A. B. B. Be C. Bl D. Bm 20. K is the symbol of A. Calcium B. Chromium C. Potassium D. Krypton
Answer:
c. iron
Explanation:
iron's atomic number is 26
How many ml of 0.5M of HNO3 would be needed to react with 85ml of 0.75M of KOH
Answer: 127.5ml
Explanation:
To calculate the volume of acid, we use the equation given by neutralization reaction:
[tex]n_1M_1V_1=n_2M_2V_2[/tex]
where,
[tex]n_1,M_1\text{ and }V_1[/tex] are the n-factor, molarity and volume of acid which is [tex]HNO_3[/tex]
[tex]n_2,M_2\text{ and }V_2[/tex] are the n-factor, molarity and volume of base which is KOH.
We are given:
[tex]n_1=1\\M_1=0.5M\\V_1=?mL\\n_2=1\\M_2=0.75M\\V_2=85mL[/tex]
Putting values in above equation, we get:
[tex]1\times 0.5\times V_1=1\times 0.75\times 85\\\\V_1=127.5mL[/tex]
Thus 127.5 ml of 0.5M of HNO3 would be needed to react with 85ml of 0.75M of KOH
Combustion and corrosion are similar reactions because they both... A) release Carbon Dioxide as a product B) release oxygen as a product C) require oxygen as a reactant D) Have a metal as a reactant
Answer:
B. release oxygen as a product
Explanation:
Balance the equation: FeSO4(s) + O2(g) + H2O(l) = Fe(OH)3 + H2SO4
Answer: 4 FeSO4(s) + O2(g) + 10 H2O(l) ---> 4 Fe(OH)3 + 4 H2SO4
Explanation:
FeSO4(s) + O2(g) + H2O(l) = Fe(OH)3 + H2SO4
In other to balance the equation, the total number of atoms of each element on the Left Hand Side (LHS) of the equation must be equal to the total number of atoms on the Right Hand Side (RHS) of the equation.
Add the following coefficients to the equation;
FeSO4 = Add 4, H20 = Add 10, Fe (OH)3 = Add 4 and H2SO4 = Add 4
By doing this, you will discover that the total number of atoms on bothe sides of the equation are balanced; thus we have;
4 FeSO4(s) + O2(g) + 10 H2O(l) ---> 4 Fe(OH)3 + 4 H2SO4
The minimum amount of unstable atoms needed to produce an uncontrolled chain reaction is called _____.
atomic mass
mass number
critical mass
why do airbags fill evenly with gas?
Answer:
The signal from the deceleration sensor ignites the gas-generator mixture by an electrical impulse, creating the high-temperature condition necessary for NaN3 to decompose. The nitrogen gas that is generated then fills the airbag. hope that helps love!
how do shinny pots or pans reflect light
Answer:
Yes they do
Explanation:
This is because the light that shines on the pots and pans reflect back considering that they are shinny.
Answer:
Polished shiny surfaces reflect light because they have a even surface.
Explanation:
The polished shiny surfaces being smooth and lustrous, absorb very little amount of light and reflect more.
Pls Brainliest!!
What is the average atomic mass of chlorine if 75.8% of chlorine atoms are 35/17 CL with a mass of 34.9589 amu and 24.2% are 37/17 CL with a mass of 36.9659 amu?
Answer:
Explanation:So if a neutron or two is added or removed from the nucleus, then the ... For example Cl–35 has an atomic mass of 35 u (17 protons and 18 neutrons), while Cl–37 ... Calculate the mass contribution of chlorine–35 to the average relative atomic mass ... Which of the following are isotopes of 3517Cl? 1735Cl. 3517Cl. 3717Cl.
13)
Which emission causes the atomic number of a nuclide to decrease by 2 and its mass
number to decrease by 4?
Answer:
Alpha decay.
Explanation:
When an element undergoes alpha decay, the resulting daughter nuclei will have a decrease of 4 in the mass number and a decrease of 2 in the atomic number.
In the attached photo, 235 92U undergo alpha decay to produce 231 90Th.
Comparing the mass number and atomic number of 235 92U with that of 231 90Th we can see that the mass of 231 90Th reduced by 4 and the atomic number reduce by 2 indicating that the parent nucleus is undergoing alpha decay.
Answer:
Alpha emission
Explanation:
The alpha particle is akin to a helium nucleus hence it is often referred to as a helium nucleus. The alpha particle has four mass units and a charge if +2.
Alpha emission is one of the emissions undergone by radioactive nuclei. When an atom undergoes alpha emission, it is easy to notice because the mass number of the nucleus decreases by four while its atomic number decreases by two. The daughter nucleus is now found two places behind its parent in the periodic table.
An example of alpha emission is shown below;
23592U→42He+23190Th
Thorium is four mass units less than U-235 and two places behind uranium in the periodic table as explained above.
The two products that are formed when a solution of HNO3 and a solution of NaOH react are water and:
NaNO2.
NaNO3.
NaHNO.
NaHNO3.
Answer: NaNO3 (Sodium Trioxonitrate (V) )
Explanation:
The equation of the reaction is; HNO3 + NaOH -----> H2O + NaNO3
Answer: its B
Explanation:
Blood rich in carbon dioxide was called venous blood, as it was believed that only the veins carried this type of blood. Based on what you know about the circulatory system, explain why this statement is incorrect.
Answer:
Yes is incorrect
Explanation:
not all veins carry blood rich in CO2 , the pulmonary vein carries blood with O2 which means that not all veins carry blood rich in CO2
state two characteristics of matter demonstrated by
diffusion brownian motion ? and I want small answer
please halp me quick it is argent
1.matter is made up of small particles
2.particles of matter are in constant random motion
Explanation:
1.Particles eg of salt can be crashed into smaller particles 2.When you sprinkle pollen grains on water in a beaker and observe using a hand lens U'll see they are moving randomly
HELP ME PLEASE !!!!!!!!!!
Answer:
1, deductive reasoning
2, hypothesis
3, law
4, objective
5, presupposition
6, qualitative
7, quantitative
8, subjective
9, theory
please at least answer one! Determine the formula mass of each of the substances below.
1. CaCl2
2. NH4OH
3. AgCH3COO
4. Ba3(PO4)2
5. Al2(CO3)3
6. Zn(NO3)2
Someone please help! I've been stuck on this for hours :(
Answer:
Explanation:
1. 40.08 + 35.45(2) = 110.98
2. 14.01 + 1.01(5) + 16.00 = 35.06
3. 107.87 + 12.01(2) + 1.01(3) + 16.00(2) = 165.91
4. 137.33(3) + 30.97(2) + 16.00(8) = 601.93
5. 26.98(2) + 16.00(9) + 12.01(3) = 216.06
6. 65.39 + 14.01(2) + 16.00(6) = 189.41
Check me if I'm wrong.
balance each equation by entering the correct coefficients.
Answer:
5SiO2 + 2CaC2 --> 5Si + 2CaO + 4CO2
4NH3 + 5O2 --> 4NO + 6H2O
Which of the following cannot be tested by science?
A) How adrenaline affects the mating behaviors of animals
B)How emotion affects the quality of a painting
C)How gravity affects the movement of an object
D)How temperature affects the sex of offspring
I'm pretty sure it's A)
the term biodiversity means the variety of organism (true or false)
Answer:
true
Explanation:
16. Sulphuric acid + Sodium hydroxide is equal to Sodium sulfate + water.
a. Acid + metal
b. Acid + alkalic.
c. Acid + carbonated.
d. None of the above
Which is correct?
Answer:
The answer is B.
Explanation:
In the reaction above, Sulphuric acid is an acid and Sodium hydroxide is an alkaline. It will produce salt and water in the product side.
Which of the following is NOT a true state-
ment about gases?
Answer:
Unsure there's not enough information to answer
Explanation:
Which of the following is NOT a true statement about gases?
What do a mole of magnesium (Mg) and a mole of iron (Fe) have in common?
A.
their number of atoms
B.
their number of molecules
C.
their number of electrons
D.
their number of protons
Answer:
A. Their numbers of atoms
Explanation:
1. What Volume of HCl is generated if 3.44 g of Cl2 are reacted at STP? [tex]H_{2} (g) + Cl_{2}(g) -\ \textgreater \ 2HCl(g)[/tex] 2. What volume does 4.87 mol of Kr have at STP? 3. What pressure of HCl is generated if 3.44 g of Cl2 are reacted in 4.55 L at 455 K?
Answer:
1. 2.17 dm^3
2. 109.1 dm^3
3. 0.398 atm
Explanation:
1. Considering the equation of the reaction;
Number of moles of chlorine gas in 3.44 g= 3.44/2(35.5)= 0.0485 moles
Since we can see from the equation that
1 mole of chlorine gas yields 2(22.4) dm^3 of HCl
0.0485 moles of chlorine gas yields 0.0485 moles × 2(22.4)dm^3/1= 2.17 dm^3
2. Note that 1 mole of Kr occupies 22.4 dm^3
Therefore 4.87 moles of Kr will occupy 4.87 × 22.4 dm^3/1 = 109.1 dm^3
3. From PV= nRT
n= 0.0485 moles
V= 4.55 L
T= 455 K
P= the unknown
R= 0.082 atm dm^3K-1mol-1
P= nRT/V
P= 0.0485 moles × 0.082 atm dm^3K-1mol-1 × 455/4.55
P= 0.398 atm
Answer:
1) volume of HCl = 2.17 L HCl
2) volume of Kr = 109.09 L
3) Pressure of HCl = 0.796 atm
Explanation:
Step 1: Data given
Mass of Cl2 : 3.44 grams
Molar mass Cl2 = 70.9 g/mol
STP = 1atm and 273 K
Step 2: The balanced equation
H2(g) + Cl2(g) → 2HCl(g)
Step 3: Calculate moles of Cl2
Moles Cl2 = mass/ molar mass Cl2
Moles Cl2 = 3.44 grams / 70.9 g/mol
Moles Cl2 = 0.0485 moles
Step 4: Calculate moles HCl
For 1 mol H2 we need 1 mol Cl2 to produce 2 moles HCl
For 0.0485 moles Cl2 we'll have 2*0.0485 = 0.097 moles HCl
Step 5: Calculate volume of HCl
For 1 mol we have 22.4 L
For 0.097 moles we have 22.4 * 0.097 = 2.17 L HCl
Step 1: Data given
Moles of Kr = 4.87 moles
STP = 1 mol, 1atm and 273 K and 22.4 L
Step 2: Calculate volume at STP
1 mol has a volume of 22.4 L
4.87 moles has a volume of 22.4 L * 4.87 = 109.09 L
Step 1: Data given
Mass of Cl2 : 3.44 grams
Molar mass Cl2 = 70.9 g/mol
Volume = 4.55 L
Temperature = 455 K
Step 2: The balanced equation
H2(g) + Cl2(g) → 2HCl(g)
Step 3: Calculate moles of Cl2
Moles Cl2 = mass/ molar mass Cl2
Moles Cl2 = 3.44 grams / 70.9 g/mol
Moles Cl2 = 0.0485 moles
Step 4: Calculate moles HCl
For 1 mol H2 we need 1 mol Cl2 to produce 2 moles HCl
For 0.0485 moles Cl2 we'll have 2*0.0485 = 0.097 moles HCl
Step 5: Calculate pressure of HCl
p*V = n*R*T
⇒with p = the pressure of HCl = TO BE DETERMINED
⇒with V = the volume = the volume of HCl = 4.55 L
⇒with n = the moles of HCl = 0.097 moles
⇒with R = the gas constant = 0.08206 L*atm/mol*K
⇒with T = the temperature = 455 K
p = n*R*T / V
p = (0.097 moles * 0.08206L*atm/mol*K * 455 K) / 4.55 L
p = 0.796 atm
What is the total mass of Kr-42 remaining in a 20-mg sample after 48.8 hours?
(1) 2.5 mg
(2) 5.0 mg
(3) 10 mg
4) 20 mg
Answer:
2.5milligram
Explanation:
Due to Kr-42 the 20mg will diluted to the experinental evluation
I need help with number 6
(d) greenhouse effect
What volume of 0.500 M HNO₃(aq) must completely react to neutralize 100.0 milliliters of 0.100 M KOH(aq)?
Answer:
v = 500 milliliters
Explanation:
[tex]HNO_{3}[/tex] ⇒ [tex]H^{+} + NO^{3-}[/tex]
[tex]KOH[/tex] ⇒ [tex]K^{+} + OH^{-}[/tex]
1 [tex]H^{+}[/tex] to 1 [tex]OH^{-}[/tex]
[tex]\frac{0,5}{V} = \frac{0,1}{100} \\\\v * 0,1 = 50\\v = 500 milliliters[/tex]
Which of the following statements about water are true 1) water cover 75% of Earth 2) once water is used it can never be reused 3) only 3% of Earth’s water is fresh 4) water comprises the majority of all plants and animals.
Answer:
I guess the 1st one idk
How many atoms are contained in 97.6 g of platinum (Pt)?
Answer:
3.01 * 10 ^ 23 atoms of Pt
Explanation:
1 mole of Pt contains 6.02 * 10 ^ 23 atoms of Pt
195.084 g of Pt has 6.02 * 10 ^ 23 atoms of Pt
97.6 g = .5 moles so
97.6 g of Pt has 3.01 * 10 ^ 23 atoms of Pt
The 97.6 grams of platinum contains [tex]3.011\times 10^{23}[/tex] atoms.
Given:
The mass of platinum = 97.6 grams
To find:
The number of platinum atoms in 97.6 grams.
Solution:
Mass of platinum = 97.6 g
Moles of platinum =[tex]\frac{97.6g}{195.084 g/mol}=0.500 mol[/tex]
According to the mole concept:
1 mole = Avogadro Number = [tex]N_A=[/tex] [tex]6.022\times 10^{23} atoms/ molecules/ions[/tex]
The number of platinum atoms in 0.500 moles of platinum:
[tex]=0.500\times 6.022\times 10^{23} atoms\\\\=3.011\times 10^{23} atoms[/tex]
The 97.6 grams of platinum contains [tex]3.011\times 10^{23}[/tex] atoms.
Learn more about the mole concept here:
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