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2 years ago

Can someone answer 2 for me please?

Chemistry

2 answers:

KIM [24]2 years ago

6 0

Answer: the answer is B it remains constant

Explanation:

The total amount of energy and matter in the Universe remains constant, merely changing from one form to another.

harkovskaia [24]2 years ago

5 0

Answer:

i think its b but i could be wrong

Explanation:

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A man heats a balloon in the oven. If the balloon initially has a volume of 0.4 liters and a temperature of 20 degrees celsius,

Airida [17]

Answer:

0.714 liter.

Explanation:

Given:

The balloon initially has a volume of 0.4 liters and a temperature of 20 degrees Celsius.

It is heated to a temperature of 250 degrees Celsius.

Question asked:

What will be the volume of the balloon after he heats it to a temperature of 250 degrees Celsius ?

Solution:

By using:

$PV=nRT$

Assuming pressure as constant,

V∝ T

Now, let K is the constant.

V = KT

Let initial volume of balloon , $V_{1}$ = 0.4 liter

1000 liter = 1 meter cube

1 liter = $\frac{1}{1000} m^{3} = 10^{-3} m^{3$

0.4 liter = $0.4\times10^{-3}=4\times10^{-4} m^{3}$

And initial temperature of balloon, $T_{1}$ = 20°C = (273 + 20)K

= 293 K

Let the final volume of balloon is $V_{2}$

And a given, final temperature of balloon, $T_{2}$ is 250°C = (273 + 250)K

= 523 K

Now, $V_{1}$ = $KT_{1}$

$4\times10^{-4}=K\times293\ (equation\ 1 )$

$V_{2}$ = $KT_{2}$

$=K\times523\ (equation 2)$

Dividing equation 1 and 2,

$\frac{4\times10^{-4}}{V_{2} } =\frac{K\times293}{K\times523}$

K cancelled by K.

By cross multiplication:

$293V_{2} =4\times10^{-4} \times523\\V_{2} =\frac{ 4\times10^{-4} \times523\\}{293} \\ = \frac{2092\times10^{-4}}{293} \\ =7.14\times10^{-4}m^{3}$

Now convert it into liter with the help of calculation done above.

$7.14\times10^{-4} \times1000\\7.14\times10^{-4} \times10^{3} \\0.714\ liter$

Therefore, the volume of the balloon be after he heats it to a temperature of 250 degrees Celsius is 0.714 liter.

5 0

2 years ago

To determine the concentration of SO4 2– ion in a sample of groundwater, 100.0 mL of the sample is titrated with 0.0250 M Ba(NO3

Brrunno [24]

Answer:

1.87x10⁻³ M SO₄²⁻

Explanation:

The reaction of SO₄²⁻ with Ba²⁺ (From Ba(NO₃)₂) is:

SO₄²⁻(aq) + Ba²⁺(aq) → BaSO₄(s)

<em>Where 1 mole of SO₄²⁻ reacts per mole of Ba²⁺</em>

<em />

To reach the end point in this titration, we need to add the same moles of Ba²⁺ that the moles that are of SO₄²⁻.

Thus, to find molarity of SO₄²⁻ we need to find first the moles of Ba²⁺ added (That will be the same of SO₄²⁻). And as the volume of the initial sample was 100mL we can find molarity (As ratio of moles of SO₄²⁻ per liter of solution).

<em>Moles Ba²⁺:</em>

7.48mL = 7.48x10⁻³L ₓ (0.0250moles / L) = 1.87x10⁻⁴ moles of Ba²⁺ = Moles of SO₄²⁻

<em>Molarity SO₄²⁻:</em>

As there are 1.87x10⁻⁴ moles of SO₄²⁻ in 100mL = 0.1L, molarity is:

1.87x10⁻⁴ moles of SO₄²⁻ / 0.1L =

8 0

3 years ago

Which of these statements about enzymes is true?

allochka39001 [22]

Enzymes are organic catalysts
and catalysts generally increase rate of reaction by lowering activation energy
C is the answer

7 0

3 years ago

Which is an electronic tool that can be used to improve science?

Vanyuwa [196]

The answer is probeware

6 0

2 years ago

Read 2 more answers

1. We have new knowledge of how charge can be transferred from one object to another

NeX [460]

Charge can be transferred from one object to another in three way conduction, polarization, and friction

Whenever electrons are transferred between objects, neutral matter becomes charged and three ways this can occur are referred to as conduction, polarization, and friction conduction means when there is direct contact between materials that differ in their ability to give up or accept electrons when two different materials are rubbed together, there is a transfer of electrons from one material to the other material and this causes one object to become positively charged (the electron loser) and the other object to become negatively charged (the electron gainer)

Here given object is water + balloon; balloon + wall; tape then you rub a balloon against your clothes and it sticks to the wall, you are adding a surplus of electrons (negative charges) to the surface of the balloon the wall is now more positively charged than the balloon and we tested the conductivity of deionized water positively charged

Know more about charge transferred one object to another

brainly.com/question/28661233

#SPJ1

5 0

1 year ago