Calculate the mass, in grams, of 0.245 moles of nickel(11) perchlorate

38.7 g

Explanation:

first you find the molar mass of Nickle(II) Perchlorate

Nickle = 58.693 g/mol

Perchlorate is Chlorine and Oxygen combined

Molar mass of chlorine is 35.453 g/mol

Oxygen = 15.999 g/mol but since it has 4 oxygen atoms combined with chlorine you have to multiply 15.999 by 4 which is 63.996 add all the masses together and that gives you 158.142. Since you have moles you multiply the moles by the molar mass which looks like this. 0.245 * 158.142 which equals 38.74479 but with sign figs it is 38.7g as your final answer. Ask me if you are confused about something.

43.452

step-by-step explanation:

284 times .153 = 43.452

first let us lay out the formula for potential

and kinetic energy:

pe = mgh

ke = (mv^2)/2

where: m=mass, v=velocity, g=gravitational

acceleration, h=height

calculating for mass using the known values of

pe:

340j = m (9.81 m/s^2) (50ft) (1m/3.28ft)

m = 2.27 kg

the law of conservation of energy states that

energy is neither created nor destroyed. therefore, the change in kinetic

energy from 50 ft to 35 ft would be equal to the change in potential energy

from 50 ft to 35 ft. however it would be opposite in signs since one is losing

while other is gaining.

ke(35ft) – ke(50ft) = - [ pe(35ft) – pe(50ft]

ke(50ft) = 0 since the brick is initially at rest

ke(35ft) = 340j - 2.27kg (9.81 m/s^2) (35ft)

(1m/3.28 ft)

ke(35ft)

= 102.38 j