Answer: -
37.5 g of NaCl are in 250 g of a 15.0% (by weight) solution.
Explanation: -
Total mass = 250 g
Percentage of NaCl = 15.0 %
= 
Thus
= 
Number of grams of NaCl present = 
= 37.5 g
Answer:
The correct answer is B.
Explanation:
The molecule of water has 2 atoms of hydrogen and 1 atom of oxygen.
The ratio of masses are given as:

This illustrates the law of definite proportions which is also known as law of constant compositions .
The law states that 'the elements combining to form compound always combine in a fixed ratio by their mass.'
Whereas :
Law of multiple proportion states that when two elements combine with each other to form more than one compounds , the mass of one element with respect to the fixed mass of another element are in ratio of small whole numbers.
Law of conservation of mass states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form.
In a balanced chemical reaction ,total mass on the reactant side must be equal to the total mass on the product side.
Law of conservation of energy states that energy can neither be created nor be destroyed but it can only be transformed from one form to another form.
Sunscreen can have negative effects on corals and other marine organisms under certain circumstances.
Atomic Numbers are the number of protons within the nucleus,
which is 58 here.
Atomic Number=58
Mass Number is the sum of the protons and neutrons in the nucleus,
=58+82
Mass Number=140
Periodic symbol of this isotope is entirely dependent on the number of protons, 58, which corresponds to the element Cerium, abbreviated as Ce in the periodic table.
Periodic Symbol=Ce
If 50.75 g of a gas occupies 10.0 L at STP, 129.3 g of the gas will occupy 25.48 L at STP.
<h3>How to calculate volume?</h3>
The volume of a gas at STP can be calculated using the direct proportion method.
According to this question, 50.75 g of a gas occupies 10.0 L at STP, then 129.3g of the same gas will occupy the following:
= 129.3 × 10/50.75
= 25.48L
Therefore, if 50.75 g of a gas occupies 10.0 L at STP, 129.3 g of the gas will occupy 25.48 L at STP.
Learn more about volume at: brainly.com/question/12357202
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