As you sit on a dock, you notice a wave crest pass. You count another 10 wave crests in the next 15 seconds. What is the frequency of these waves?
A. 10 Hz
B. 15 HZ
C. 0.667 Hz
D. 1.5 Hz

Frequency of the waves = 0.667 Hz

Explanation:

Given:

Number of waves = 10

Time taken = 15 seconds

Find:

Frequency of the waves.

Computation:

⇒ Frequency of the waves = Number of waves / Time taken

⇒ Frequency of the waves = 10 / 15

⇒ Frequency of the waves = 0.667 Hz

"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"