Answer:
138 mg
Explanation:
A company is testing drinking water and wants to ensure that Ca content is below 155 ppm (= 155 mg/kg), that is, <em>155 milligrams of calcium per kilogram of drinking water</em>. We need to find the maximum amount of calcium in 890 g of drinking water.
Step 1: Convert the mass of drinking water to kilograms.
We will use the relation 1 kg = 1000 g.
Step 2: Calculate the maximum amount of calcium in 0.890 kg of drinking water
Answer:
K₂Cr₂O₇(s) ⇒ 2 K⁺(aq) + Cr₂O₇²⁻(aq)
Explanation:
Potassium dichromate (K₂Cr₂O₇) is a strong electrolyte, that is, when dissolved in water (the medium), it dissociates in cation potassium (K⁺) and anion dichromate (Cr₂O₇²⁻). The balanced dissociation equation is:
K₂Cr₂O₇(s) ⇒ 2 K⁺(aq) + Cr₂O₇²⁻(aq)
The answer is 37.5 moles
The explanation:
1- when we have the mass of SO3 in Kg so, first we have to convert it to grams:
mass = 3 * 1000 = 3000 g
2- we need to get the molar mass of SO3 :
molar mass of SO3 = 32 + (16*3)
= 80 g/mol
3- then we can use this formula to get number of moles:
moles = mass / molar mass
= 3000 g / 80 g/mol
= 37.5 moles
Answer:
1..... nucleus
2......electron cloud
3.......protons
4........Neutrons
5..........electron
6............electrons
7...............Isotopes
8.....,...........ions
9....................charge
