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2 years ago

Which of these is an example of a chemical change?

1 answer:

5 0

A; A chemical change makes a substance that wasn't there before. Moldy cheese has a new substance, color change and an odor.

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What vaciole-like strucyure break down and recycle cell parts

kap26 [50]

<span>lysosomes should be the right answer to this question</span>

6 0

3 years ago

A sample of 4.50 g of methane occupies 12.7 dm3 at 310 K. (a) Calculate the work done when the gas expands isothermally against

valkas [14]

Answer:

(A) Work done will be 87.992 KJ

(B) Work done will be 167.4 KJ

Explanation:

We have given mass of methane m = 4.5 gram = 0.0045 kg

Volume occupies $V_1=12.7dm^3=12.7liters$

And volume is increased by $3.3dm^3$ so $V_2=12.7+3.3=16liters$

Temperature T = 310 K

Pressure is given as 200 Torr = 26664.5 Pa

(a) At constant pressure work done is given by

$W=P(V_2-V_1)=26664.5\times (16-12.7)=87992.85J=87.992kj$

(b) At reversible process work done is given by $W=nRTln\frac{V_2}{V_1}$

We have given mass = 4.5 gram

Molar mass of methane = 16

So number of moles $n=\frac{mass\ in\ gram}{mol;ar\ mass}=\frac{4.5}{16}=0.28125$

So work done $W=0.28125\times 8.314\times 310ln\frac{16}{12.7}=167.4J$

7 0

2 years ago

What is the weight of an object when the object has a mass of 22kg

Savatey [412]

Assuming the object is on earth the objects weight would be equal to its mass multiplied by the gravitational field constant

mass=22kg
g=9.80665N/kg

weight=(22 kg) (9.80665 N/kg)=215.7463N

generally g is rounded to be 10 N/kg so for any question where it asks the weight given the mass just multiply by 10 and that should suffice. In this case the answer would be 220 N

5 0

2 years ago

Helpp!!! Will mark brainlst

masya89 [10]

Answer:

i dont know

Explanation:

cuz i dont know what it wrote its too blurry

5 0

3 years ago

In nuclear fission the nucleus is divided into two or more fragments, releasing Question 8 options: protons and energy. neutrons

Dmitrij [34]

Answer:

the answer is neutrons and energy

8 0

2 years ago