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WILL MARK BRANIEST

Answer:

459.126 grams of calcium chloride is needed to prepare 2.657 L of a 1.56 M solution

Explanation:

Molarity is a measure of the concentration of a solute in a solution that indicates the amount of moles of solute that appear dissolved in one liter of the mixture. In other words, molarity is the number of moles of solute that are dissolved in a given volume.

The Molarity of a solution is determined by the following expression:

[tex]Molarity=\frac{number of moles of solute}{volume}[/tex]

Molarity is expressed in units [tex]\frac{moles}{liter}[/tex]

In this case:

Replacing:

[tex]1.56 M=\frac{Number of moles of calcium chlorine}{2.657 liters}[/tex]

Solving:

Number of moles of calcium chlorine= 1.56 M* 2.657 liters

Number of moles of calcium chlorine= 4.14 moles

In other side, you know:

Then the molar mass of the calcium chloride CaCl₂ is:

CaCl₂= 40 g/mole + 2* 35.45 g/mole= 110.9 g/mole

Now it is possible to apply the following rule of three: if in 1 mole there is 110.9 g of CaCl₂, in 4.14 moles of the compound how much mass is there?

[tex]mass=\frac{4.14 moles*110.9g}{1 mole}[/tex]

mass= 459.126 g

459.126 grams of calcium chloride is needed to prepare 2.657 L of a 1.56 M solution

Answer:

ionic

Explanation:

Answer:

1 quart of lemonade will be in the first cup

Explanation:

1/4th of a gallon is a quart

Answer:

D working alone

Explanation:

Working alone is the only option that could potentially be a safety hazard; if you have no one watching your back, errors could occur, like dropping glass or burning your hand, and no one is around to help you.

Choices A, B, and C are not correct because those are all good safety standards.

Answer:

Photo chemical is caused by the chemical reaction of light. It's initiated by the absorption of energy in the form of light.

Explanation:

When the picture is developed, the thiosulfate dissolved the silver bromide that had been exposed to light more easily than the one that had been kept in the dark,

Answer:it is D

Explanation: it is only one that makes sense

Answer: Pounds per Cubic inch(lb/in3)

Answer:

when heat gets transferred through electromagnetic waves that move through

space

Explanation:

Radiation refers to the movement of energy through space without a material medium of propagation.

Electromagnetic waves have the ability to travel through space without a material medium for propagation. For instance, the rays from the sun reach us on earth without any intervening medium. Heat from a furnace can affect an object some distance away from the furnace without an intervening medium.

These are all examples of radiation. Energy is propagated through space without the intervention of any material medium.

Answer:

[tex]\rm _{27}^{60}\text{Co} \longrightarrow \, _{-1}^{0}\text{e} + \, _{28}^{60}\text{Ni}[/tex]

Explanation:

The unbalanced nuclear equation is

[tex]\rm _{27}^{60}\text{Co} \longrightarrow \, _{-1}^{0}\text{e} + \, ?[/tex]

Let's write the question mark as a nuclear symbol.

[tex]\rm _{27}^{60}\text{Co} \longrightarrow \, _{-1}^{0}\text{e} + \, _{Z}^{A}\text{X}[/tex]

The main point to remember in balancing nuclear equations is that the sums of the superscripts and the subscripts must be the same on each side of the equation.  

Then

60 = 0 + A, so A = 60 - 0 = 60, and

27 = -1 + Z, so Z  = 27 + 1 = 28

Your nuclear equation becomes

[tex]\rm _{27}^{60}\text{Co} \longrightarrow \, _{-1}^{0}\text{e} + \, _{28}^{60}\text{X}[/tex]

Element 28 is nickel, so the balanced nuclear equation is

[tex]\rm _{27}^{60}\text{Co} \longrightarrow \, _{-1}^{0}\text{e} + \, _{28}^{60}\text{Ni}[/tex]

Answer: The air pressure at the top of the mountain is 96.9 kPa

Explanation:

To calculate the new pressure, we use the equation given by Boyle's law. This law states that pressure is directly proportional to the volume of the gas at constant temperature.

The equation given by this law is:

[tex]P_1V_1=P_2V_2[/tex]

where,

[tex]P_1\text{ and }V_1[/tex] are initial pressure and volume.

[tex]P_2\text{ and }V_2[/tex] are final pressure and volume.

We are given:

[tex]P_1=99.5kPa\\V_1=22.3L\\P_2=?\\V_2=22.9L[/tex]

Putting values in above equation, we get:

[tex]99.5\times 22.3L=P_2\times 22.9L\\\\P_2=96.9kPa[/tex]

Thus the air pressure at the top of the mountain is 96.9 kPa

Answer:

all of them except number 2

Explanation:

Answer:

1,3,4,5  the other perosn is correct

Explanation: That what my quiz said

Answer:

Approximately [tex]-74.8\; \rm kJ \cdot mol^{-1}[/tex].

Explanation:

Number the three reactions with known enthalpy changes:

[tex]\begin{aligned}& {\rm C\; (s) + O_2\; (g) \to CO_2\; (g)} & \quad \Delta H = -393.5\; \rm kJ\cdot mol^{-1}& \quad (1) \\ & {\rm H_2\; (2) + \frac{1}{2} O_2\; (g) \to H_2O\; (l)} & \quad \Delta H = -285.8\; \rm kJ\cdot mol^{-1} & \quad (2) \\ & {\rm CH_4\; (g) + 2\; O_2\; (g) \to CO_2\; (g) + 2\; H_2O\; (l)} & \quad \Delta H = -890.3\; \rm kJ\cdot mol^{-1} & \quad (3)\end{aligned}[/tex].

The goal is to find a way to combine these three reactions to obtain: [tex]\rm C\; (s) + 2\; H_2\; (g) \to CH_4\; (g)[/tex].

Assume that the three known reactions are combined in this way:

[tex]a \times (1) + b \times (2) + c \times (3)[/tex].

That corresponds to:

[tex]\begin{aligned} & a\; \mathrm{C\; (s)} + \left(a + \frac{1}{2}\, b + c\right) \; \mathrm{O_2\; (g)} + b\; \mathrm{H_2\; (g)} + c\; \mathrm{CH_4\; (g)} \\ & \to (a + c)\; \mathrm{CO_2\; (g)} + (b+ 2\,c )\; \mathrm{H_2O\; (l)}\end{aligned}[/tex].

Compare the coefficients of this reaction with that of the desired reaction:

[tex]\rm C\; (s) + 2\; H_2\; (g) \to CH_4\; (g)[/tex].

Note that some species (e.g., [tex]\rm CH_4\; (g)[/tex]) appeared on the wrong side of the equation. Their desired coefficient should be the opposite of their true coefficient. For example, the coefficient of [tex]\rm CH_4\; (g)[/tex] is supposed to be [tex]1[/tex]. However, because it appeared on the wrong side of the equation, its desired coefficient would be [tex]-1[/tex].

The coefficients of species that are not in the desired equation should be zero.

[tex]\begin{array}{|c|c|c|}\cline{1-3}\text{Species} & \text{Coefficient}& \text{Desired Coefficient} \\ \cline{1-3} \mathrm{C\; (s)}} & a & 1 \\ \cline{1-3} \mathrm{O_2\; (g)} & a + (1/2)\, b + c & 0 \\ \cline{1-3} \mathrm{H_2\; (g)} & b & 2 \\ \cline{1-3}\mathrm{CH_4\; (g)} & c & -1\\ \cline{1-3} \mathrm{CO_2\; (g)} & a + c & 0 \\ \cline{1-3} \mathrm{H_2O\; (l)} & b + 2\, c & 0\\ \cline{1-3}\end{array}[/tex].

Solve for [tex]a[/tex], [tex]b[/tex], and [tex]c[/tex]:

In other words, the desired equation is equal to [tex]1 \times (1) + 2 \times (2) - 1 \times (3)[/tex].

By Hess's Law, the enthalpy of the desired equation will be:

[tex]\begin{aligned}& 1\times \Delta H (1) + 2 \times \Delta H (2) - 1\times \Delta H(3) \\ &\approx -393.5 + 2 * (-285.8) - (-890.3) \\ &= -74.8\; \rm kJ \cdot mol^{-1} \end{aligned}[/tex].

Answer:

D.

Explanation:

It would not be gain because it would say +6 instead of -2. Having a -2 charge means it wants to loose 2 electrons so it can form a full shell of 8 electrons. It wants to be inert (stable).

- Hope that helps! Please let me know if you need further explanation.

Answer:

The planets themselves are composed of several trillions or quadrillions or more atoms. As far as hard science is concerned, it would be really hard to picture them as electrons. Conclusion: It can be said with a great accuracy that our planets are NOT huge electrons.

Rutherford's experiments showed that the mass of atoms was mostly concentrated in a very small region, with charge equal to the atomic number- the nucleus. He absolutely did not show, nor is it true, that electrons orbit the nucleus as if they were planets. That was a guess people made in trying to figure out how to picture the atom.

(Hope this helps) Sky

Answer:

2H on 3H

Explanation:

it's because Mario eh, eh, eh. now back of and habeba goodnday

Answer:

Option C

Explanation:

Dipole moment being ac vector quantity has both magnitude and direction. All bonding forces have dipole moment ranging from partially positive to negative moment.  

Net dipole moment is the dipole moment arising after summation of all the existing dipole moments. On the basis of dipole moment it is determined whether the molecule is polar or non polar.  

Hence, option c is correct

Answer:c

Explanation:

Answer:

natural selection

Explanation:

it is a biological selection of genes, whether dominant or negative.

Answer:

Before submerged 150ml

After submerged: 180ml

rock volume: [tex]180 - 150 = 30[/tex]

formula for density:

[tex] \frac{mass}{volume} = 5.38 [/tex]

[tex] \frac{175}{30} = 5.38 [/tex]

THE ANSWER IS b

prettty sure this is wrong but eh :/ probably correct

Answer:  

In sports some , examples are  using a heavier bat or racket and increasing running speed or hand speed.

Explanation:

MOMENTUM: is the  mass and the velocity, you can increase momentum by increase either of these elements

The molarity of a KCl solution if 37.3 g of KCl are dissolved in water to give a final solution volume of 500 ml is 1 M.

Molarity of a given solution is known as the total number of moles of solute per litre of the solution.  A solution that is 1.00 molar (written 1.00 M) contains 1.00 mole of solute for every liter of solution.

Molarity = (No. of moles of solute ÷ Volume of solution in liters)

The unit of molarity is mol L⁻¹.

Molarity is temperature dependent because as temperature changes, volume of the solution also changes.

Given, Mass of KCl = 37.3 g

Molar mass of KCl = 74.5 g/mol

Volume of solution = 500ml = 0.5 L

No. of moles = Mass / Molar mass = 0.5

Molarity = 0.5/0.5 = 1 M

Therefore, The molarity of a KCl solution if 37.3 g of KCl are dissolved in water to give a final solution volume of 500 ml is 1 M.

Learn more about Molarity, here:

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Answer: 50N forward

Explanation:

A woman is pushing a cart 125N forward (+125N)

Gravity is pushing 50N backwards (-50N)

A child is pushing 25N backwards (-25N)

The net force is the total sum of these forces.

125N+(-50N)+(-25N)

125N-50N-25N

125N-75N

50N forward because it's positive

Answer:

Explanation: A woman is pushing a cart 125N forward (+125N)

Gravity is pushing 50N backwards (-50N)

A child is pushing 25N backwards (-25N)

The net force is the total sum of these forces.

125N+(-50N)+(-25N)

125N-50N-25N

125N-75N

50N forward because it's positive

Answer:

1. sublimation

2.melting

3.melting  

4.sublimation

Explanation:

melting is a process when solid changes to liquid

Sublimation is the transition of a substance directly from the solid to the gas state, without passing through the liquid state.

Winds are always named from the direction it blows from

Uneven heating of Earth's surface,in turn,causes differences in air pressure at various locations. Heated air rises,creating an area of low pressure beneath. Cooler air descends, creating an area of high pressure

Answer: C) 28.8

Explanation:

Expression for rate law for first order kinetics is given by:

[tex]t=\frac{2.303}{k}\log\frac{a}{a-x}[/tex]

where,

k = rate constant

t = age of sample

a = initial amount of the reactant  = 1.000 g

a - x = amount left after decay process = 0.908 g

a) to find rate constant

[tex]4.00yr=\frac{2.303}{k}\log\frac{a}{a-x}[/tex]

[tex]k=\frac{2.303}{4.00}\log\frac{1.000}{0.908}[/tex]

[tex]k=0.024yr^{-1}[/tex]

b) for completion of half life:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

[tex]t_{\frac{1}{2}}=\frac{0.693}{k}[/tex]

[tex]k=\frac{0.693}{0.024yr^{-1}}=28.8yr[/tex]

The half-life of strontium-90 is 28.8 yr.

Answer:

Magnets stick to the fridge door because, underneath the paint, the door is made of steel. Magnets are attracted to certain metals, and if the attraction is strong enough they can hold on even when upside down. ... This means that a magnet will always be attracted to the door. But an iron nail does not have any magnetic properties. So it doesnt get attracted.

Hope this helps, Pls mark as Brainliest!!

A small magnet will stick to a refrigerator door, but a nail will not stick

because magnets attract certain types of metals.

Magnets have a strong magnetic field which is why it attracts metals such

as iron and steel. The refrigerator must have been made with iron or steel

which was why the magnet stuck to it.

Metals such as aluminium and copper aren't attracted by magnets which is

why the nails weren't attracted as a result of it being made with metals which magnets don't attract.

Read more on https://brainly.com/question/19482396

Answer:

The answer is NaOH

Explanation:

Strong bases are characterized by the fact that they dissociate completely in an aqueous solution. In this case, sodium hydroxide, NaOH, is classified as a strong base because it dissociates completely in an aqueous solution to form sodium cations, Na+, and hydroxide anions, OH−. Also, it is strong because it totally breaks in its ion. And the base which breaks totally in its atom called the strong base and which doesn't it that is a weak base.

Answer:

NaOH

Explanation:

Got it right in the test. Please mark as brainliest

Answer:

C:

Explanation:

Current flows from negative to positive.So the electrons will be moving left.

when a current is applied, positive charged copper ions (called cations) leave the anode (positive electrode) and move to the cathode (negative electrode).