Please help with this chemistry question it’s due by midnight

HF is the limiting reactant

Explanation:

The balanced equation for the reaction is given below:

SiO₂ + 4HF —> SiF₄ + 2H₂O

From the balanced equation above,

1 mole of SiO₂ reacted with 4 moles of HF.

Finally, we shall determine the limiting reactant. This can be obtained as illustrated below:

From the balanced equation above,

1 mole of SiO₂ reacted with 4 moles of HF.

Therefore, 7.5 moles of SiO₂ will react with = 7.5 × 4 = 30 moles of HF.

From the calculation made above, we can see clearly that it will take a higher amount (i.e 30 moles) of HF than what was given from the question (i.e 5 moles) to react completely with 7.5 moles of SiO₂.

Therefore, HF is the limiting reactant and SiO₂ is the excess reactant.

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

plants need sunlight, water, and carbon dioxide to make food. plants use the raw materials of water, nutrients they absorb from soil, and carbon dioxide to make sugars the plant can use. energy from the sun and chlorophyll are also needed.