All categories

3 years ago

The recommended dietary allowance for calcium for teenage children is 1,300 mg per day.

Chemistry

1 answer:

PtichkaEL [24]3 years ago

5 0

Answer:

c) 35 fl oz

Explanation:

Hello,

In this case, to compute the recommended amount of calcium that the teenager must drink, one performs the following relationship:

$8.0-fl \ oz -->298mg\\x-->1,300mg$

Solving for $x$ , one gets:

$x=\frac{8.0-fl \ oz *1,300mg}{298mg} \\x=35-fl \ oz$

Best regards.

You might be interested in

The universe contains billions of galaxies, each containing billions of stars. True or false

Tatiana [17]

True but no one know Exactly how many stars there are

8 0

3 years ago

Read 2 more answers

Según la ecuación, HNO3 + H2S ----------- NO + S+ H2O el elemento que se oxida es

Serhud [2]

Answer:

HNO3 + H2S = H2O + NO + S - Chemical Equation Balancer. Balanced Chemical Equation. 2 HNO 3 + 3 H 2 S → 4 H 2 O + 2 NO + 3 S. Reaction Information. Nitric Acid + Hydrogen Sulfide = Water + Nitric Oxide (radical) + Sulfur . Reactants.

Explanation:

5 0

3 years ago

URGENT CHEMISTRY EXPERT!

vovangra [49]

Answer:

Part 1: 7.42 mL; Part 2: 3Cu²⁺(aq) + 2PO₄³⁻(aq) ⟶ 2Cu₃(PO₄)₂(s)

Explanation:

Part 1. Volume of reactant

(a) Balanced chemical equation.

$\rm 2Na_{3}PO_{4} + 3CuCl_{2} \longrightarrow Cu_{3}(PO_{4})_{2} + 6NaCl$

(b) Moles of CuCl₂

$\text{Moles of CuCl}_{2} =\text{ 16.7 mL CuCl}_{2} \times \dfrac{\text{0.200 mmol CCl}_{2}}{\text{1 mL CuCl}_{2}} = \text{3.340 mmol CuCl}_{2}$

(c) Moles of Na₃PO₄

The molar ratio is 2 mmol Na₃PO₄:3 mmol CuCl₂

$\text{Moles of Na$_{3}$PO}_{4} = \text{3.340 mmol CuCl}_{2} \times \dfrac{\text{2 mmol Na$_{3}$PO}_{4}}{\text{3 mmol CuCl}_{2}} =\text{2.227 mmol Na$_{3}$PO}_{4}$

(d) Volume of Na₃PO₄

$V = \text{2.227 mmol Na$_{3}$PO}_{4}\times \dfrac{\text{1 mL Na$_{3}$PO}_{4}}{\text{0.300 mmol Na$_{3}$PO}_{4}} = \text{7.42 mL Na$_{3}$PO}_{4} \\\\\text{The reaction requires $\large \boxed{\textbf{7.42 mL Na$_{3}$PO}_{4}}$}$

Part 2. Net ionic equation

(a) Molecular equation

$\rm 2Na_{3}PO_{4}(\text{aq}) + 3CuCl_{2}(\text{aq}) \longrightarrow Cu_{3}(PO_{4})_{2}(\text{s}) + 6NaCl(\text{aq})$

(b) Ionic equation

You write molecular formulas for the solids, and you write the soluble ionic substances as ions.

According to the solubility rules, metal phosphates are insoluble.

6Na⁺(aq) + 2PO₄³⁻(aq) + 3Cu²⁺(aq) + 6Cl⁻(aq) ⟶ Cu₃(PO₄)₂(s) + 6Na⁺(aq) + 6Cl⁻(aq)

(c) Net ionic equation

To get the net ionic equation, you cancel the ions that appear on each side of the ionic equation.

6Na⁺(aq) + 2PO₄³⁻(aq) + 3Cu²⁺(aq) + 6Cl⁻(aq) ⟶ Cu₃(PO₄)₂(s) + 6Na⁺(aq) + 6Cl⁻(aq)

The net ionic equation is

3Cu²⁺(aq) + 2PO₄³⁻(aq) ⟶ Cu₃(PO₄)₂(s)

7 0

3 years ago

What is the ph of a solution of 0.700 m kh2po4, potassium dihydrogen phosphate?

GalinKa [24]

Molal or molar? There is a difference

4 0

3 years ago

Choose the best statement of the octet rule from those listed below atoms lose 8 electrons to become valent atoms lose 8 electro

Mnenie [13.5K]

Answer:

atoms tend to react in order to gain 8 valence electrons

Explanation:

The octet rule describes the tendency of atoms of elements to react in order to have eight electrons in their valence shell. This is because having eight valence electrons confers stability to the atoms of these elements in the compounds they form.

The octet rule only does not apply to the transition elements or the inner transition elements as only the s and p electrons are involved. the electronic configuration in atoms having an octet is s²p⁶.

For example, sodium atom has one valence electron in its valence shell but a complete octet in the inner shell; it will react with chlorine atom which has seven valence electrons to form a stable compound, sodium chloride by donating its one valence electron in order to have an octet. Similarly, the chlorine atom will then have an octet by accepting the one electron from sodium atom.

7 0

3 years ago