Asample of water is heated from 10.0°c to 15.0°c by the addition of 125 j of heat. what is the
mass of the water?

5.97 g of water

Q = m × c × ΔT

In this case;

Quantity of heat, Q = 125 Joules

Change in temperature = 15°C - 10°C

                                       = 5°C

We know that the specific heat capacity of water is 4.186 J/g°C

Therefore, to get the mass we first rearrange the formula;

Mass = Q ÷ cΔT

        = 125 J ÷ (5°C × 4.186 J/g°C)

        = 5.97 g

Therefore, the mass of water is 5.97 g

The mass of a sample of water that is heated from 10.0°C to 15.0°C is 0.00595 kilograms.

Given the following data:

We know that the specific heat capacity of water is 4200 J/kg°C.

To find the  mass of the water:

Mathematically, quantity of heat is given by the formula;

Where:

Making mass the subject of formula, we have:

Substituting into the formula, we have:

Mass = 0.00595 kilograms

Therefore, the  mass of the water is 0.00595 kilograms.

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pre-sliced bread is a relatively recent development in baking technology. previous to that, it was always sold in a bakery in daily-made contiguous loaves with no wrapping, and was moderately perishable, usually being used with a day or two (which is why every bakery had a discounted “day-old” bread table.) therefore, pre-sliced bread would grow stale quickly. the hard crust provided a protective layer, and once the exposed dry slice left from the previous cut was removed, the interior was still soft.

what keeps bread soft is the moisture retained in the crumb (the light spongy part that’s not crust). the reason the crust develops is the surface of the dough gets exposed to hot dry air during baking which browns the outer layer and seals it, preventing all the moisture from escaping the dough. longer exposure to air will also eventually cause your bread to lose flavor and become stale.

people were used to cutting slices as they needed them and storing bread in a specially-made wooden or metal breadbox or pail with a lid to preserve it longer, but the first automatically sliced commercial loaves were produced on july 6, 1928, in chillicothe, missouri, using a machine invented by otto rohwedder, an iowa-born, missouri-based jeweler.[1] pre-sliced bread would indeed dry out, were it not for another 20th century technology: the plastic bag. bread could now be pre-sliced, and if the enclosing bag remains sealed as much as possible, the bread will remain soft and fresh for longer than if sitting unwrapped on a shelf or enclosed in a bread box that is not air-tight. sealed packaging meant bread could also be sold on store shelves and eliminate frequent trips to a bakery.

sealing bread in a plastic bag had another effect: the moisture in the loaf will re-distribute into the crust and soften it, which is sometimes more pleasing in a sandwich - especially for children whose teeth might not yet be strong enough to tear through a hard crust. a homemade loaf of bread can be sealed in a bag overnight and the crust will become soft like store-bought sandwich bread.

these were novel changes in how bread was produced and sold, which led to the coining of the phrase “the greatest thing since sliced bread.”

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.