Answer:
#2 Empirical formula _Na3S4O9____
Molecular formula ___Na6S8O18__
Explanation:
MCu: 63,5 g/mol
4 × mCu = 63,5×4 = 254 g
254g ------ 0,39%
Xg ---------- 100%
X = (254×100)/0,39
X = 65128,2 g/ mol <<<< molar mass
Answer:
Mass = 713.4 ×10⁻⁴ g
Explanation:
Given data:
Number of moles of calcium phosphate = 2.3×10⁻⁴ mol
Mass of calcium phosphate = ?
Solution:
Formula:
Number of moles = mass/molar mass
Molar mass of calcium phosphate is 310.18 g/mol
by putting values,
2.3×10⁻⁴ mol = mass / 310.18 g/mol
Mass = 2.3×10⁻⁴ mol × 310.18 g/mol
Mass = 713.4 ×10⁻⁴ g
Molarity is moles per liter. Therefore you must covert grams->moles by dividing 9.82 by the molar mass of lead IV nitrate. Then convert mL->L. Once you have those two numbers you can plug them into the formula Molarity = mol/L.
Answer:
2 atm
Explanation:
Chemical reactions are carried out at a certain rate. Sometimes that rate is quite slow, so we want to speed things up, which is usually used by increasing temperature, increasing pressure or adding a catalyst (a substance that increases the rate without changing itself).
If this is the case, then, when writing a chemical equation, we state these special conditions over a right arrow.
Now let's look at the answers:
- 25°C is a value and unit of temperature
- ∆ is a symbol that denotes change
- 2 atm is a value and unit of pressure (atmosphere is old unit for pressure)
- Pt is a chemical symbol for platinum, an element often used as a catalyst.
So, the correct answer is C) 2 atm
