Answer:
An acid is a chemical that is posining or sometimes not
Explanation:
This is the best I could explain brainliest
Teresa has taken three tests worth 100 points each. Her scores are 85, 93, and 88. She has one test left to take.
To get an average score of 90, what must the sum of all her test scores be?
a.
400
c.
600
b.
360
d.
300
Answer:
SOrry it makes me writer sotufjksankdn
Explanation:
The chemical equation for zinc in hydrochloric acid is: Zn + HCI = ZnCl2 + H2
Does the above equation demonstrate the law of conservation of mass as it is currently written? Explain why or why not.
Answer: No it does not
Explanation:
The law of conservation of mass states that mass is neither created nor destroyed and in this equation you start with 1 molecule of Cl and 1 of H, but on the reactants side you end up with 2 of each. To make it follow the law of conservation of mass you would have to balance the equation
A gas has an initial pressure of 120 kPa, a volume of 23 liters, and a temperature of 20°C. If the pressure is raised to 150 kPa the new volume is 17 liters, what is the new temperature of the gas? *
A.100 K
B.0.003 K
C.270.7 K
D.18.4 K
How many moles of aluminum sulfide will be produced if 12 moles of Sg react?
Answer:
Molar mass = [9(12.0)+8(1.01)+4(16.0)] = 180.1 g/mol Moles = 112 g 1 mol x 180.1 g = 0.622 mol (3 sig figs)
Explanation:
Please help me I will give brainliest to the first correct answer
Answer:
OPTIC B) HEPT-HOPE IT IS HELPFUL
When temperature drops, (for example from 20 degrees celsius to 10 degrees celsius)
a.) energy increases
b.) particles move slower
c.) particles collide more often
d.) pressure increases
Answer:
In the Celsius scale each degree is one part of 100 degrees. This is because in this scale the difference between boiling and freezing temperatures of water is 100 ° - 0 ° = 100 °, so one degree Celsius is one part of 100.
In the Farhenheit scale, each degree is one part of 180 degrees. This is because in this scale the difference between the boiling and freezing temperatures are 212 ° - 32 ° = 180°, so one degree Fahrenheti is one part of 180.
That means that 1 °C is a larger amount than 1 °C, so 20°C is a larger amount than 20°F.
Conclusion: 20 degree change represents a larger change in Celsius scale.
Explanation:
In the Celsius scale each degree is one part of 100 degrees. This is because in this scale the difference between boiling and freezing temperatures of water is 100 ° - 0 ° = 100 °, so one degree Celsius is one part of 100.
In the Farhenheit scale, each degree is one part of 180 degrees. This is because in this scale the difference between the boiling and freezing temperatures are 212 ° - 32 ° = 180°, so one degree Fahrenheti is one part of 180.
That means that 1 °C is a larger amount than 1 °C, so 20°C is a larger amount than 20°F.
Conclusion: 20 degree change represents a larger change in Celsius scale.
How many ml of a 6.00M HNO would be required to prepare 200ml of a 2.50M
solution?
83.33ml
72.98ml
86.23ml
64.98ml
Answer:
83.33ml
Explanation:
Firstly, let's notice that 200ml are equal to 0.2L
M=number of moles of the solute ÷ number of liters. Let's call the number of liter by x:
2.5=x÷0.2
x=2.5×0.2
x=0.5
It means you'll need 0.5 mol of HNO. But your solution have 6 moles per liter, so how much do you need? Divide the moles by 12 to have 0.5, so now you need to divide the liter per 12 too. The liter is equal to 1000ml, so:
1000ml÷12=83.33ml
the tissue which continually forms new cells in plants
Answer:
Meristematic Tissues. Tissues where cells are constantly dividing are called meristems or meristematic tissues. These regions produce new cells.
Explanation:
thank me later
Does heat flow out of the atmosphere (HQ)
change during the day?
Answer:
The heat flow into Earth's atmosphere varies as the Sun rises and sets, gradually increasing during the day and falling to zero at night.
Explanation:
Heat radiates from the ground into the lower atmosphere. In conduction, heat moves from areas of more heat to areas of less heat by direct contact. Warmer molecules vibrate rapidly and collide with other nearby molecules, transferring their energy.
How many formula units are there in 14.50 moles of any compound?
___X 10^___formula units
Answer:
8.73 × 10²⁴ formula units
Explanation:
To calculate the number of formula units a substance contain, we multiply the number of moles by Avagadro number (6.02 × 10²³)
number of formula units = 14.50 moles × 6.02 × 10²³
= 87.29 × 10²³
= 8.73 × 10²⁴ formula units.
how many moles are in 0.14g of Nitrogen, N2?
Answer:
0.01 moles
Explanation:
14 g contains 1 mole
0.14g contains> (0.14*1)/14
= 0.01 moles
Gas particles that are at low temperature and high pressure and are close to changing phases are considered:
a)Real Gases
b)Ideal Gases
c)Both Ideal and Real Gases
Balance the following equation:
Cr + __02 +_Cr203
Answer:
4Cr + __302 -->_2Cr203.....
PLEASE QUICKLY. I'll give BRAINLIEST. A sample contains 25% parent isotope and 75% daughter isotopes. If the half-life of the parent isotope is 72 years, how old is the sample?
144 years old
216 years old
288 years old
360 years old
From the calculations and the principles of radioactivity, the age of the parent isotope is 144 years
What is radioactivity?The term radioactivity has to do with the spontaneous decay of a substance.
We know that we have about 25% parent isotope still remaining hence;
[tex]0.693/t1/2 =2.303/t log No/N\\When N =0.25 No and t1/2 = 72 years\\0.693/72 =2.303/t log No/0.25No\\0.0096 = 2.303/t *0.60206\\0.0096 = 1.3865/t\\t = 1.3865/0.0096\\t =144 years[/tex]
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Answer:
A. 144 years old
Explanation:
Examine the food chain below: In this specific food chain, the _______ eats plants for food. A. caterpillar B. sunshine C. bobcat D. leaf
Pls answer this Il give brainiest question in picture ty
Answer:
c
Explanation:
troposphere is the answer
A Starting substance in a chemical reaction is called a _______________.
1. reactant
2. product
3. chemical reaction
4. physical reaction
Answer:
1.)REACTANT
These starting substances of a chemical reaction are called the reactants, and the new substances that result are called the products.The concentration of carbon-14 in a piece of wood from an ancient burial mound indicates that two half-lives of this radioisotope have passed. If the half-life (t 1/2) for carbon-14 is 5730 years, approximately how many years ago did this sample of wood die?
If the half-life for carbon-14 is 5730 years, then it will take 11,460 years to complete die of this sample.
What is half life period?Half life period is a time of decay in which concentration of reactant is left half of its initial concentration, means half of the reactant will convert into product.
Total time of decay will be calculated as:
T = (t)ⁿ, where
t = half life time = 5730 years
n = number of half lives = 2 (given)
On putting values, we get
T = (5730)² = 11,460 years
Hence required time for decay is 11,460 years.
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Answer:
The first part is 5 and the second part is 28,650
why metal in the middle of metal activity series can't be obtained by heating ors in air
Answer:
See Explanation
Explanation:
The way by which a metal is obtained from its ore is determined by the chemical reactivity of the metal.
Metals that are highly reactive are chiefly obtained by electrolysis of the metal salt. These metals are found high up in the metal activity series.
Metals that are at the middle of the series are moderately reactive and are obtained by electrolysis or by reduction since they still form ionic salts.
Metals that are far lower in the series can only be obtained by heating them in air because they are mostly unreactive.
Hence, moderately reactive metals at the middle of the series are not obtained by roasting in air.
Someone please help me
Answer:reflection
Explanation:
High levels and long periods of stress can increase a person’s risk for many diseases.
True
False
Answer:
true
Explanation:
2Cr^3 + 3Zn(s) -> 2Cr(s) + 3Zn^2 + (aq) which reactant is reduced and which is oxidicided
Answer:
Cr is oxidised
and
Zn is reduced
[ Reduced reactant ] :
Cr^( + 3 ) + 3 e^( - 1 ) ===》 Cr^( 0 )
_____________________________
[ Oxidicided reactant ] :
Zn^(0) ===》Zn^( + 2 ) + 2 e^( - 1 )
112 g of aluminum carbide react with 174 g water to produce methane and aluminum hydroxide in the reaction shown below.
2 Al4C3(s) + 12 H2O(l) → 3 CH4(g) + 4 Al(OH)3(s)
If aluminum carbide is the limiting reactant, how many moles of the excess reactant are left over
a
37.3 mol
b
4.68 mol
c
7.33 mol
d
131.94 mol
Answer: 4.999 moles of excess reactant will be left over.
Explanation:
Limiting reagent is defined as the reagent which is completely consumed in the reaction and limits the formation of the product.
Excess reagent is defined as the reagent which is left behind after the completion of the reaction.
The number of moles is defined as the ratio of the mass of a substance to its molar mass.
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] .....(1)
Given mass of aluminium carbide = 112 g
Molar mass of aluminium carbide = 143.96 g/mol
Putting values in equation 1:
[tex]\text{Moles of aluminium carbide}=\frac{112g}{143.96g/mol}=0.778mol[/tex]
For the given chemical reaction:
[tex]2Al_4C_3(s)+12H_2O(l)\rightarrow 3CH_4(g)+4Al(OH)_3(s)[/tex]
By the stoichiometry of the reaction:
2 moles of aluminium carbide reacts with 12 moles of water
So, 0.778 moles of aluminium carbide will react with = [tex]\frac{12}{2}\times 0.778=4.668 mol[/tex] of water
Given mass of water = 174 g
Molar mass of water = 18 g/mol
Putting values in equation 1:
[tex]\text{Moles of water}=\frac{174g}{18g/mol}=9.667mol[/tex]
Moles of excess reactant (water) left = 9.667 - 4.668 = 4.999 moles
Hence, 4.999 moles of excess reactant will be left over.
The volume of a gas is 2250 mL at 290 kPa what will the volume be when the pressure is reduced to .9 atm
Answer:
7178.22 mL
Explanation:
Applying,
PV = P'V'................. Equation 1
Where P = Initial pressureof gas, V = Initial volume of gas, P' = Final pressure of gas, V' = Final volume of gas.
make V' the subject of the equation
V' = PV/P'.............. Equation 2
From the question,
Given: V = 2250 mL, P = 290 kPa, P' = 0.9 atm = (101×0.9) = 90.9 kPa
Substitute these values into equation 2
V' = (2250×290)/90.9
V' = 7178.22 mL
When 1 mol of methane is burned at constant pressure, −890 kJ/mol of energy is released as heat. If a 1.67 g sample of methane is burned at constant pressure, what will be the value of ∆H
Answer:
[tex]\Delta H=-92.7kJ[/tex]
Explanation:
Hello there!
In this case, according to the given information, we can infer that 890 kJ of energy are released when 1 mole of methane is burned; however, to find the total heat when 1.67 grams are burned, we first need to calculate the moles in this mass of methane:
[tex]1.67gCH_4*\frac{1molCH_4}{16.04gCH_4}=0.104molCH_4[/tex]
And thus, for calculating the resulting ∆H, we proceed as follows:
[tex]\Delta H=-890kJ/mol*0.104mol\\\\\Delta H=-92.7kJ[/tex]
Regards!
Use the equation below:
2Na + Cl2 ==> 2NaCl
+ O
How many grams of NaCl are produced when 1.25 moles of Cl2 reacts with Na?
Explanation:
2/1×1.25
=2.5 mole of NaCl are produced
weight of NaCl produced = moles × molar mass of NaCl
weight of NaCl produced = 2.5×58.5
weight of NaCl produced =146.5 grams
Water can keep engines operating at low temperatures. Which property of water most likely gives it this ability?
A. it boils at around 100°C
B. it has a high heat capacity
C. it is a good lubricant
D. it can change from water to ice
Answer:
B: it has a high heat capacity
Explanation:
When any material has a high specific heat capacity/ heat capacity, it doesn't heat or cool very fast. So water can absorb more heat from the engine and can keep the engine cool or at low temperature for a longer period of time.
Explain the reason that the atomic emission spectrum of hydrogen contains only four lines.
A)
The hydrogen atoms form a continuous series of quantized energy levels
that transmute at a variety of frequencies.
B)
Hydrogen atoms contain a limited number of quantized energy levels that
emit radiation at a limited number of frequencies.
C)
Many hydrogen atoms accomodate an array of quantized energy levels that
can release energy at a progression of frequencies.
A hydrogen atom consists of a sequence of quantized energy levels that
incorporate radiation only from consecutive frequencies.
D)
Answer:
Though a hydrogen atom has only one electron, it contains a large number of shells, so when this single electron jumps from one shell to another, a photon is emitted, and the energy difference of the shells causes different wavelengths to be released... hence, mono-electronic hydrogen has many spectral lines.
Explanation:
thank me later
The reason that the atomic emission spectrum of hydrogen contains only four lines is the hydrogen atoms form a continuous series of quantized energy levels that transmute at a variety of frequencies.
What is atomic emission spectrum of hydrogen?The emission spectrum of hydrogen consist of numerous spectral series, the wavelength is postulated by Rydberg formula.
The reason behind the lines of spectrum is the transition of electron between two energies.
Thus, the correct option is A.
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when chlorine gas is passed through potassium Bromide solution Potassium Chloride and bromine are formed which is a more reactive non metal bromine or chlorine
[tex] \boxed{\boxed{\huge{ \mathbf{ \underline{ Answer} \: \: ✓ }}}}[/tex]
In a displacement reaction, more reactive element displaces less reactive element from its compound and from the above reaction we observed that, Chlorine displaces bromine from its compound (KBr) to form Potassium chloride (KCl), therefore Chlorine is more reactive non - metal.
The equation for above reaction is :
[tex] \large\boxed {\mathrm{2KBr + Cl_2 \rightarrow 2KCl + Br_2}}[/tex]
_____________________________
[tex]\mathrm{ ☠ \: TeeNForeveR \:☠ }[/tex]
Balance the following equation: _H2+ __02 - __ H20
Answer:
2
H
2
+
O
2
=
2
H
2
O
Explanation:
From the original equation, you first need to write each component separately.
H
2
+
O
2
=
H
2
O
Left side: H = 2 ; O = 2 (number based on the subscript)
Right side: H = 2 ; O = 1 (number based on the subscripts; no subscript means that the element is just 1)
Notice that the number of H is already balance but the number of O is not. In order to balance the O, you need to multiply the element by 2, but you CANNOT do this by simply changing the subscript.
Hence,
H
2
+
O
2
=
2
H
2
O
Left side: H = 2 ; O = 2
Right side: H = 2 x 2 = 4 ; O = 1 x 2 = 2
Now, notice that the number of O is now balance (both are 2) but the number of H is not (since
H
2
O
is a substance and not an element, you need to multiply everything by 2). So, what to do?
You also multiply the left side H by 2. Hence,
2
H
2
+
O
2
=
2
H
2
O
Left side: H = 2 x 2 = 4 ; O = 2
Right side: H = 2 x 2 = 4 ; O = 1 x 2 = 2
The equation is now balanced.