The distance from earth to the moon is approximately 3.84x10^5 km. how long would it take a radio wave with the frequency 7.25x10^5 hz to travel from earth to the moon

The time that would  take   a radio wave with the frequency of 7.25 x 10^5 Hz  to travel from  earth to the moon is    1.28  sec

 Calculation

Time =  distance / speed

distance =  3.84 x 10 ^5 km

convert  Km to m

 1 Km= 1000 m

3.84 x10^5km= ? m

 by cross multiplication

= (3.84 x 10^5 km x 1000 m) / 1 km = 3.84 x 10 ^8 m

Speed  of light=  3.0  x 10^8 m/s

therefore time =  3.84  x10^8 m / 3.0  x10^8 m/s =  1.28  sec

i had this on my unit activity, i can you if you are a plato student. are you a plato student?

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2