Hello,
Work is done when a force causes an object to move in the same direction that the force is applied..... Friction reduces efficiency because when two surfaces slide past each other, friction resists their motion, and in real machines, some input work is always used to overcome friction.
Hope this helps!!!! Happy Holidays!!!! (:
Answers:
1st: 189.6 g/mol
2nd: 0.1357 L
3rd: 1.41 M
Explanation:
Finding Molar Mass:
SnCl2 = <u>Tin(II) Chloride</u>
Tin has a molar mass of <u>118.71 g/mol</u>
Chloride has a molar mass of <u>35.453 g/mol</u>
Chloride*2 = <u>70.906</u>
<u>118.71 + 70.906 ≈ 189.6 g/mol</u>
Finding Liters of Solution:
L = mL/1000
135.7 mL / 1000 = <u>0.1357</u>
Finding Molarity:
molarity = <u>moles of solute / liters of solution</u>
M = (36.4g / 189.6g) / 0.1357 L = <u>1.41 M</u>
Hope this helped ;)
I think that the answer is A because if you think about water for an example. When water turns into ice, it's still technically water, just the molecules are frozen. The water is physically changed. It could also see why you think it is B but I don't think so completely. It doesn't really make sense to me. So I'd choose A. It's definitely not C or D.
Answer: The heat energy produced is 53831.25KJ
Explanation:
METHANE is the main component of natural gas. It can undergo combustion reaction in air with a bright blue flame to produce carbondioxide and water. The heat of reaction (enthalpy) is negative because heat is absorbed during the chemical reaction. To calculate the heat energy produced by the combustion of one kilogram (1 kg) of methane the following steps are taken:
Molecular mass of methane =16 gm/mol.
So moles of 1 kg methane =
Given mass of methane ÷ molecular weight of methane
But the given mass = 1kg = 1000g
Therefore,
moles of 1000g methane = 1000÷16
= 62.5 moles
Hence, energy evolved = (moles of methane) × (heat of combustion)
Therefore,
heat energy produced= 62.5 × (-861.3kj)
= -53831.25kj
