Your town is at sea level, and it is a comfortable room-
temperature day. The speed of sound in air at this temperature
is about 343 m/s. If a siren from the firehouse takes 0.200
seconds to arrive at your school, how far is your school from
the firehouse? _meters

68.6 m

Explanation:

Speed is defined as distance covered per unit time and expressed as

S=d/t

Where d is distance and t is speed.

Making d the subject of the above formula then

d=st

Substituting 343 m/s dor s and 0.200 s for s then

d=343*0.2=68.6 m

Therefore, the distance is 68.6 m

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"