Answer:
A
Explanation:
The statement made by Zoe as follows "We can do better. We must eat healthier and exercise. Will you join me?” is an effective conclusion because it leaves a lasting impression for the audience.
How is an effective conclusion made?Public speakers are those who speak to a group of people in a structured manner.
However, asides presenting a spectacular body message, the conclusion must leave a lasting impression on the audience to enable them practice what was presented.
According to this question, Zoe made a conclusive statement as follows: "We can do better. We must eat healthier and exercise. Will you join me?”. This statement is an effective conclusion because it makes a lasting impression.
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How many molecules of nitrogen gas are found in 0.045 L of nitrogen gas at STP
Answer:
1.2 × 10²¹ molecules
Explanation:
Step 1: Given data
Volume of nitrogen gas (V): 0.045 LConditions: Standard temperature (273.15 K) and standard pressure (1 atm)Step 2: Calculate the number of moles corresponding to 0.045 L of nitrogen gas at STP
At STP, 1 mole of nitrogen gas occupies 22.4 L.
0.045 L × 1 mol/22.4 L = 2.0 × 10⁻³ mol
Step 3: Calculate the number of molecules in 2.0 × 10⁻³ moles of nitrogen
We will use Avogadro's number: there are 6.02 × 10²³ molecules in 1 mole of molecules of nitrogen gas.
2.0 × 10⁻³ mol × 6.02 × 10²³ molecules/1 mol = 1.2 × 10²¹ molecules
Calcium hydroxide, Ca(OH)2, is an ionic compound with a solubility product constant, Ksp, of 6.5×10–6. Calculate the solubility of this compound in pure water.
Answer: The solubility of this compound in pure water is 0.012 M
Explanation:
Solubility product is defined as the equilibrium constant in which a solid ionic compound is dissolved to produce its ions in solution. It is represented as [tex]K_{sp}[/tex]
The equation for the ionization of the is given as:
[tex]Ca(OH)_2\rightarrow Ca^{2+}+2OH^-[/tex]
By stoichiometry of the reaction:
1 mole of [tex]Ca(OH)_2[/tex] gives 1 mole of [tex]Ca^{2+}[/tex] and 2 mole of [tex]OH^-[/tex]
When the solubility of [tex]Ca(OH)_2[/tex] is S moles/liter, then the solubility of [tex]Ca^{2+}[/tex] will be S moles\liter and solubility of [tex]OH^-[/tex] will be 2S moles/liter.
[tex]K_{sp}=[Ca^{2+}][OH^{-}]^2[/tex]
[tex]6.5\times 10^{-6}=[S][2S]^2[/tex]
[tex]S=0.012M[/tex]
Thus solubility of this compound in pure water is 0.012 M
Use the above steps to balance the reaction for the combustion of methane.
____CH4 + ___O2→ ____CO2 + ___H2O
Answer:
__1__CH4 + __2_O2→ __1__CO2 + _2__H2O
The level of mercury in a barometer falls as the air pressure falls.
True
False
Real answers only or you will be reported and banned from brainly
Answer:True
Explanation:
how conditions on Earth would be different if its axis of rotation were vertical instead of tilted.
Answer:
there would be different times because the sun and moon are in different places and one side would be sunny for a long time
Explanation:
why is the volume of hydrogen is doubled the volume of oxygen in electrolysis of water?
Answer:
The volume of the hydrogen produced is always twice the volume of the oxygen produced, because water contains two atoms of hydrogen for each atom of oxygen.
True/False: A virus could have a mutation that makes it more transmissible (higher
chance of spreading).
Answer True
Explanation:
True or False: If bubbles are produced when two reactants are mixed, a chemical reaction has occurred.
Answer:
True
Explanation:
Because yes
Answer:
true because that is a reactant or the chemical
Explanation:
Silicon can be made by heating a mixture of sand (silicon dioxide) with magnesium
powder.
The equation for this reaction is shown below.
SiO2 (s)+ 2Mg (s) → 2MgO (s) + Si (s)
Calculate the mass of silicon dioxide needed to make 1 g of silicon.
Relative atomic masses: O = 16; Si = 28
Mass = ?
Answer:
[tex] \frac{60}{28} = \frac{15}{7} [/tex]
100 pts HORTICULTURE (HURRY)
The hundredweight is the common way of evaluating crop yield for which of the following crops?
A. wheat
B. soy
C. rice
D. corn
Answer:
Option A and C
Explanation:
Generally yield of wheat and rice crop is measured in terms of hundredweight. It is also known as centum weight or quintal. one quintal is equal to 100 Kg. It is used primarily in United States of America and British reign. In India quintal is used to measure the yield of wheat and rice
Hence, option A and C is the correct answer
Answer:
Option C, Rice
Explanation:
Rice is measured in hundredweight as stated in the lesson, wheat isn't mentioned to be measured by hundredweight.
You need 267 mL of .25M NaCl,
but the only supply of NaCl you
have
is 1.75M NaCl. How do you prepare
the required solution?
To prepare 267 mL of 0.25M NaCl, we need to take 38.29 mL of 1.75M NaCl solution and add water to it until it makes the final volume up to 267 mL.
We need to prepare the solution of 0.25 M NaCl using 1.75 M NaCl solution, we can use the dilution formula:
[tex]C_1V_1 = C_2V_2[/tex]
where [tex]C_1[/tex], [tex]V_1[/tex] is the concentration and the volume of the initial solution, [tex]C_2[/tex], [tex]V_2[/tex] is the concentration and the volume of the final solution.
We know the final concentration and the final volume that we are required to make. So we can use the above relation to find [tex]V_1[/tex] of the solution:
[tex]V_1 = (C_2 * V_2) / C_1[/tex]
Now after substituting the values in the relation, we get:
[tex]V_1 = (0.25 M x 267 mL) / 1.75 M\\V_1 = 0.03829 L or 38.29 mL[/tex]
So to prepare 267 mL of 0.25M NaCl, we need to take 38.29 mL of 1.75M NaCl solution and add water to it until it makes the final volume up to 267 mL.
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You have been shipwrecked on a deserted island with no running water/fresh water, you have your clothes and a plastic bag containing your phone out of
charge and some sunscreen) How are you going to survive and escape?
Answer:
i have no clue
Explanation:
can any one solve this quiz plz
Answer:
1. It is stoichiometric.
2. O2 is the limiting reactant.
3. 9.0 g of C2H6 remain unreacted.
4. 17.6 g of CO2.
5. 85.2%.
Explanation:
Hello there!
In this case, for the given chemical reaction:
[tex]2C_2H_6+7O_2\rightarrow 4CO_2+6H_2O[/tex]
We can see that:
1. It is stoichiometric and is balanced because the reactants yields the products according to the law of conservation of mass.
2. In this part, it is possible to calculate the moles of ethane by using its molar mass:
[tex]n_{C_2H_6}=15g*\frac{1molC_2H_6}{30.08g} =0.50molC_2H_6[/tex]
And the moles of oxygen by knowing that one mole is contained in 22.4 L at STP:
[tex]n_{O_2}=\frac{1mol}{22.4L} *15.68L=0.7molO_2[/tex]
Thus, by calculating the moles of carbon dioxide product by each reactant, we can identify the limiting one:
[tex]n_{CO_2}^{by\ C_2H_6}=0.50molC_2H_6*\frac{4molCO_2}{2molC_2H_6} =1.0molCO_2\\\\n_{CO_2}^{by\ O_2}=0.70molO_2*\frac{4molCO_2}{7molO_2} =0.4molCO_2\\[/tex]
Thus, since oxygen yields the fewest moles of CO2 product, we infer it is the limiting reactant.
3. In this part, we calculate the mass of C2H6 that actually react first:
[tex]m_{C_2H_6}^{reacted}=0.4molCO_2*\frac{2molC_2H_6}{4molCO_2}*\frac{30.08gC_2H_6}{1molC_2H_6} =6.0gC_2H_6[/tex]
Thus, the leftover of ethane (C2H6) as the excess reactant is:
[tex]m_{C_2H_6 }^{leftover}=15g-6.0g=9.0g6.0C_2H_6[/tex]
4. Since 0.4 moles of carbon dioxide were produced, we use its molar mass to calculate the mass as its theoretical yield:
[tex]m_{O_2}^{theoretical}=0.4molCO_2*\frac{44gCO_2}{1molCO_2}=17.6gCO_2[/tex]
5. Finally, the percent yield is gotten by dividing the actual yield by the theoretical one:
[tex]Y=\frac{15g}{17.6}*100\%\\\\Y=85.2\%[/tex]
Best regards!
Please help me, I really don't want to fail but I don't know how to do this
Answer:
A)
4, 7, 4, 6
B)
12 moles
Explanation:
[tex] NH_{3}(g) + O_{2}(g) \: → NO_{2} + H_{2}O(g)[/tex]
__↑______↑
8.00 mol | 14.00 mol
________________
[tex] NH_{3}(g) + O_{2}(g) \: → NO_{2} + H_{2}O(g)[/tex]
You can turn this into a system of variables which are solvable.
To do this, create variables for the coefficients of each compound in the reaction respectively.
[tex] a(NH_{3}(g)) + b(O_{2}(g)) → \\c(NO_{2}) + d(H_{2}O(g))[/tex]
Because to be balanced, the count of atoms in each element of the compound correspond to the coefficient of the variable in that compound so that the count of the left (reactant) side is set equal to the right (product) side.
a corresponds to the coefficient of the first compound, b corresponds to the coefficient of the second compound, c corresponds to the coefficient of the third compound, and d corresponds to the coefficient of the fourth compound.
(Reactant = Product)
Reactant: 1a [N] Product: 1c.
Reactant: 3a [H] Product: 2d.
Reactant: 2b [O] Product: 2c + 1d.
Thus the system is:
1a = 1c
3a = 2d
2b = 2c + 1d.
Then just use the substitution methods to solve.
Can someone help me please I am doing a test!!.
Your lips are more sensitive to touch than your forehead. What is different about the touch receptive fields in the lips compared to the forehead?
(Mark the one best answer.)
A There are more touch receptive fields in the lips.
B The touch receptive fields are bigger in the lips.
C The touch receptive fields are more sensitive in the lips.
D The touch receptive fields are used more often in the lips
Answer:
c i think
Explanation:
which electrons of an atom take part in a bond formation
Answer:
The electrons in the outermost electron shell are responsible for forming chemical bonds. These electrons are also known as valence electrons. Chemical bonds are formed when the outermost electron shells are not completely filled and atom needs more (or less) electrons to completely fill the outermost shell.
Explanation:
8. (07.05 LC)
Which statement is correct about the rate of most chemical reactions? (5 points)
1.It increases when the concentration of reactants decreases.
2.It does not depend on the concentration of reactants.
3.It increases when the temperature increases.
4.It does not depend on the temperature.
Answer: 3.It increases when the temperature increases.
Explanation:
The speed of most chemical reactions increase as if the temperature of those same reactions increase as well. This is because a higher temperature allows for reactants to gain the necessary activation energy needed to react.
Enzymes are another reason. Enzymes are catalysts in reactions which reduce the activation energy needed for a reaction to occur and enzymes work best in certain higher temperatures - not too high - so this also leads to the reaction speed increasing due to temperature increases.
Answer:
It increases when the temperature increases.
Explanation:
I took the test and the other guy is right ;)
what does the t cell do to your body?
Answer: it's part of the immune system that focuses on specific foreign particles. Rather than generically attack any antigens, T cells circulate until they encounter their specific antigen. As such, T cells play a critical part in immunity to foreign substances !
Explanation:
what particle has a mass & charge?
a. alpha particle
b. beta particle
c. gamma ray
Answer:
A. Alpha Particle
Explanation:
I think i could be wrong
A wave traveling through air meets an object and bounced off its flat surface
at a new angle. Which statement best describes what has happened to the
wave?
A. The object reflected the wave.
B. The object caused the wave to refract.
C. The object absorbed the wave's energy.
D. The object had a slit in its surface that diffracted the wave.
SUBMIT
When a wave moves through the air and comes into contact with an object, it hits its flat surface from a new angle, causing the wave to refract.
When a wave passes through one material and moves through another, how does its direction change?When waves cross the boundary between two different materials, their speed changes. For example, light waves refract when they pass through glass to air. Refraction is the effect that causes them to change direction as a result. When water waves move from deep water to shallow water (or the other way around), they refract light.
When a wave traveling through the air comes into contact with an object and bounces off its flat surface, what happens?
When waves bounce back from a surface they can't pass through, this is called reflection. When waves enter a new medium at an angle and begin traveling at a different speed, refraction occurs. Diffraction happens when waves spread out as they travel around impediments or through openings in obstructions.
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If the velocity of the spacecraft is 250 m/s and the asteroid is pushed back –25 m/s, what is the mass of the asteroid? Assume there is no net force on the system. 100 kg 6,250 kg 10,000 kg 6,250,000 kg
Answer:10,000 kg
Explanation:I went on my calculator and did 1,000 × 250 ÷ 25 or -25 to get 10,000 or -10,000 ;)
How many moles are represented by 86.5 g of Ca(OH)2?
*please help fast*
Answer:
30 2 the second power
Explanation:
Calcium hydroxide, commonly known as hydrated lime or slaked lime, is a soft white powder that is used as a primary ingredient in the chemical industry.
What is Calcium Hydroxide?Its chemical formula is Ca(OH)2. When calcium oxide and water are combined, it produces.
There are two hydroxide ions (OH) in the molecule for every calcium ion (Ca2+). The substance is ionic, and both electrolytic and aqueous dissociations result in calcium and hydroxide ions.
When water is added to dry portland cement to create concrete, this reaction takes place, and the mixture warms up and releases heat. An alternative method of manufacturing entails an aqueous double displacement reaction between sodium hydroxide and calcium chloride.
Therefore, Calcium hydroxide, commonly known as hydrated lime or slaked lime, is a soft white powder that is used as a primary ingredient in the chemical industry.
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Which One Is the Wrong One?
Answer:
I would say the second one it's the wrong
a 20.0 mL solution of HCl with a pH if 1.500 is diluted by the addition of 80.0 additional mL of water, so that the total solution volume is 100.0 mL. What is the new pH of the solution after the dilution?
a.) 7.000
b.) 2.199
c.) 3.320
d.) 12.599
answer is a
Explanation:
What type of reaction is
illustrated?
Ca + CuSO4 -> CaSO4 + Cu
A. synthesis
B. decomposition
C. single
replacement
How is 2Mg+O2= 2MgO balanced?
Answer:
A half-reaction can be written to represent reduction. At the same time the magnesium atoms become ions, the oxygen atoms become –2 anions by gaining one electron each. By combining these two reactions, we have an oxidation reaction and a re- duction reaction, that are perfectly balanced.
Explanation:
Regroup terms.
2Mg+2O=2mgo
Subtract 2Mg2Mg from both sides.
2O=2mgo-2Mg
Factor out the common term 2.
2O=2(mgo-Mg)
Cancel 2 on both sides.
O=mgo−Mg
What important ingredients do you need to create a fertilized egg
Answer:
In the 1970s, Epel and other researchers showed that calcium is the essential factor that sparks development in eggs. As calcium levels rise, metabolic changes occur that cause the egg to divide and form into an embryo.
Explanation:
Explain why the following are made of thermosetting plastics.
(a) Saucepan handles
(b) Electric plugs/switches/plug boards
Answer:
a: they're used in saucepan handles 'cause they don't soften when heated and also 'cause they cant be bent easily.
b: thermosetting plastics are bad electricity conductors. they don't get moulded and are also hard and strong.
The reason Senators are in office for 6 years is....( No links pls or I’m reporting you :)
1) To separate Senators from the whims of the
general public.
2) to save money in elections
3) Because Senators are required to be older
than representatives
HELPP asap I’ll mark you as brainlister
Answer:
The solution is nopolar
Explanation:
Answer:
The solution does NOT conduct electricity.
Explanation:
Nonelectrolytes are usually held together by covalent bonds rather than ionic ones.