Final answer:
To find the grams of NaCl in a 0.90% w/w isotonic solution, you multiply 0.90% by the total mass of the solution (1000 grams). This gives you 9 grams of NaCl in 1.00 kg of solution. Option C is correct.
Step-by-step explanation:
The question asks how many grams of sodium chloride (NaCl) are contained in 1.00 kg of a 0.90% (w/w) isotonic salt solution. To find the answer, we use the definition of weight/weight percent (w/w%). The 0.90% w/w NaCl means that there are 0.90 grams of NaCl in every 100 grams of the solution.
To calculate the grams of NaCl in 1.00 kg of the solution, we use the following steps:
First, convert the weight of the solution from kilograms to grams: 1.00 kg = 1000 grams.
Since we know the percent concentration (0.90%), we can calculate the mass of NaCl as follows:
Mass of NaCl = 0.90% of 1000 g = (0.90/100) × 1000 g = 9 grams.
Therefore, there are 9 grams of NaCl in 1.00 kg of the 0.90% w/w NaCl solution, which corresponds to answer choice (c).