Answer:
30 g
Explanation:
<em>For CaCl₂</em>
3CaCl₂ + 2Na₃PO₄ ⟶ Ca₃(PO₄)₂ + 6NaCl
Moles of CaCl₂ = <em>c</em>×<em>V</em> = 5.0 × 10⁻² × 2.0 = 0.100 mol
Moles of Na₃PO₄ = 0.100 × 2/3 = 0.0667 mol
Mass of Na₃PO₄ = 0.0667 × 163.94 = 10.9 g
———————————————————
<em>For Mg(NO₃)₂
</em>
3Mg(NO₃)₂ + 2Na₃PO₄ ⟶ Mg₃(PO₄)₂ + 6NaCl
Moles of Mg(NO₃)₃ = <em>c</em>×<em>V</em> = 8.5 × 10⁻² × 2.0 = 0.170 mol
Moles of Na₃PO₄ = 0.170 × 2/3 = 0.113 mol
Mass of Na₃PO₄ = 0.113 × 163.94 = 1 g
—————————————————
Total mass of Na₃PO₄ = 10.9 + 18.6 = 29.5 g
To two significant figures, mass = 30 g
<span>88 and 84 are mass numbers
the mass number of an element is the sum of the number of protons and the number of neutrons (in which they are each equal to 1 unit (amu))
the number of protons is always the same for a given element (e.g. any C atom has 6 protons), but the number of neutrons varies. Two atoms of the same element (number of protons) with a different number of neutrons are called "isotopes".
So the two strontium atoms differ by 4 neutrons. 84Sr has four neutrons less than 88Sr</span>
33 - 15 = 18
This element is P-33
Answer:

Explanation:
Hello!
In this case for the solution you are given, we first use the mass to compute the moles of CuNO3:

Next, knowing that the molarity has units of moles over liters, we can solve for volume as follows:

By plugging in the moles and molarity, we obtain:

Which in mL is:

Best regards!