To find the mass percent of the sodium hydroxide in the solution, we first need to find the total mass of the solution. We do this by adding the mass of the sodium hydroxide (6g) to the mass of the water (50g). This gives us a total mass of 56g for the solution.
Next, we divide the mass of the sodium hydroxide (6g) by the total mass of the solution (56g). This gives us a ratio of 0.10714285714285714.
Now, to get the percentage, we multiply the ratio by 100. This gives us approximately 10.71%.
Rounding this number to the nearest whole percent, it shows that the mass percent of the sodium hydroxide in the solution is approximately 11%.
Based on our calculations, none of the provided choices match the calculated value. The closest option is (A) 12%, but it is not a perfect match. We would advise to check the given data again.