Final answer:
The number 9.14 × 10^-4 moles per liter expressed in standard notation is 0.000914, which means the decimal is moved four places to the left.
Step-by-step explanation:
To express the number 9.14 × 10^-4 moles per liter in standard notation, you move the decimal place to the left if the exponent is negative. Here you move the decimal four places to the left because of the exponent -4.
The number in standard notation will be 0.000914. This corresponds to option (a) 0.000914.