Hardness is defined as calcium and magnesium ion content. Since most hardness is caused by carbonate mineral deposits and does not distinguish calcium and magnesium ions, hardness is usually reported as parts per million (ppm) of calcium carbonate (CaCO3, by weight). A water supply with a hardness of 100 ppm contains the equivalent of 100 g of CaCO3 in 1 million g of water or 0.1 g in 1 L of water (or 1000 g of water since the density of water is about 1 g/mL). For a water supply with a hardness 134 ppm, what is its hardness in mol/L?

Question

Hardness is defined as calcium and magnesium ion content. Since most  hardness  is  caused  by  carbonate  mineral deposits and does not distinguish calcium and magnesium ions,  hardness  is  usually  reported  as  parts  per  million  (ppm)  of  calcium  carbonate  (CaCO3, by weight).  A water supply with a hardness of 100 ppm contains the equivalent of 100 g of CaCO3 in 1 million g of water or 0.1 g in 1 L of water (or 1000 g of water since the density of water is about 1 g/mL). For a water supply with a hardness 134 ppm, what is its hardness in mol/L?

Dr. Neutron · Accepted Answer

1st: 100ppm= 0.1g/L or0.100g/L so 134ppm= 0.134g/L. 2nd:.134g/L divide by molar mass of CaCO3 which is 108.09g/mol. Gram and gram cancel out left you with mole and liter Answer: .00124 mol/L

evan · Answer

caco3 = 100.08g/mol

Step-by-Step Bot · Answer

To determine the hardness of a water supply in mol/L, we need to convert the hardness from ppm (parts per million) to mol/L. First, we need to calculate the number of moles of CaCO3 in 1 L of water. 1 L of water = 1000 g of water In 1000 g of water, the hardness is 0.1 g of CaCO3. To convert grams to moles, we need to use the molar mass of CaCO3, which is 100.0869 g/mol. So, the number of moles of CaCO3 in 0.1 g is: 0.1 g / 100.0869 g/mol = 0.0009998 mol Therefore, the hardness in mol/L is approximately 0.0009998 mol/L.

Explain Bot · Answer

To determine the hardness of a water supply in mol/L, we need to convert the hardness from ppm (parts per million) to mol/L (molar concentration). First, let's convert the hardness from ppm to g/L. Given: Hardness = 134 ppm We know that 1 ppm is equivalent to 1 mg/L (parts per million is the same as milligrams per liter). Therefore, the hardness in g/L can be calculated as: Hardness (g/L) = Hardness (ppm) * 1 mg/L * 1 g/1000 mg Substituting the given value of hardness in ppm: Hardness (g/L) = 134 ppm * 1 mg/L * 1 g/1000 mg Hardness (g/L) = 0.134 g/L Next, we need to convert the hardness from g/L to mol/L. To convert g/L to mol/L, we need to know the molar mass of calcium carbonate (CaCO3), which is: - Calcium (Ca): 40.08 g/mol - Carbon (C): 12.01 g/mol - Oxygen (O): 16.00 g/mol (x 3 because there are 3 oxygen atoms in CaCO3) Molar mass of CaCO3 = 40.08 g/mol + 12.01 g/mol + (16.00 g/mol * 3) = 100.09 g/mol Now, we can calculate the hardness in mol/L: Hardness (mol/L) = Hardness (g/L) / Molar mass (g/mol) Substituting the given value of hardness in g/L and the molar mass of CaCO3: Hardness (mol/L) = 0.134 g/L / 100.09 g/mol Hardness (mol/L) = 0.001339 mol/L Therefore, a water supply with a hardness of 134 ppm has a hardness of approximately 0.001339 mol/L.