What is the frequency of an event?Group of answer choices

Probability

Degree

Expected occurrence

Identification

Answer:

Temperature and humidity

Explanation:

Crystallization occurs in super saturated solution. These are the solutions that have solute to solvent ratio of 2:1 or more. Typical honey is 70% sugar and 20% water (the solute concentration is too high).  

Two things cause honey to crystallize.

1. Temperature
2. Humidity level

If temperature is lowered the rate of crystallization increases. This is because at low temperature the molecules of solvent come closer and the space between them reduces. This causes the additional solute molecules to be pushed up to form crystals.  

Secondly, humidity also plays a key role. If the humidity reduces, the water molecules evaporates from honey into air. This increases the relative concentration of the solute inside the honey, which causes the honey to crystallize.  

Answer: The mass of excess reagent left is 20.48 g

Explanation:

To calculate the number of moles, we use the equation:

     .....(1)

• For sulfur:

Given mass of sulfur = 50 g

Molar mass of sulfur = 32 g/mol

Putting values in equation 1, we get:

• For fluorine gas:

Given mass of fluorine gas = 105 g

Molar mass of fluorine gas = 37.99 g/mol

Putting values in equation 1, we get:

The chemical equation for the reaction of sulfur and fluorine gas follows:

By Stoichiometry of the reaction:

3 moles of fluorine gas reacts with 1 mole of sulfur

So, 2.76 moles of fluorine gas will react with = of sulfur

As, given amount of sulfur is more than the required amount. So, it is considered as an excess reagent.

Thus, fluorine gas is considered as a limiting reagent because it limits the formation of product.

Moles of excess reagent (sulfur) left = 1.56 - 0.92 = 0.64 moles

• Now, calculating the mass of sulfur from equation 1, we get:

Molar mass of sulfur = 32 g/mol

Moles of sulfur = 0.64 moles

Putting values in equation 1, we get:

Hence, the mass of excess reagent left is 20.48 g

Earth is a truly unique in its abundance of water. Water is necessary to sustaining life on Earth, and helps tie together the Earth's lands, oceans, and atmosphere into an integrated system. Precipitation, evaporation, freezing and melting and condensation are all part of the hydrological cycle - a never-ending global process of water circulation from clouds to land, to the ocean, and back to the clouds. This cycling of water is intimately linked with energy exchanges among the atmosphere, ocean, and land that determine the Earth's climate and cause much of natural climate variability. The impacts of climate change and variability on the quality of human life occur primarily through changes in the water cycle. As stated in the National Research Council's report on Research Pathways for the Next Decade (NRC, 1999): "Water is at the heart of both the causes and effects of climate change."

The ocean plays a key role in this vital cycle of water. The ocean holds 97% of the total water on the planet; 78% of global precipitation occurs over the ocean, and it is the source of 86% of global evaporation. Besides affecting the amount of atmospheric water vapor and hence rainfall, evaporation from the sea surface is important in the movement of heat in the climate system. Water evaporates from the surface of the ocean, mostly in warm, cloud-free subtropical seas. This cools the surface of the ocean, and the large amount of heat absorbed the ocean partially buffers the greenhouse effect from increasing carbon dioxide and other gases. Water vapor carried by the atmosphere condenses as clouds and falls as rain, mostly in the ITCZ, far from where it evaporated, Condensing water vapor releases latent heat and this drives much of the the atmospheric circulation in the tropics. This latent heat release is an important part of the Earth’s heat balance, and it couples the planet’s energy and water cycles.

The major physical components of the global water cycle include the evaporation from the ocean and land surfaces, the transport of water vapor by the atmosphere, precipitation onto the ocean and land surfaces, the net atmospheric transport of water from land areas to ocean, and the return flow of fresh water from the land back into the ocean. The additional components of oceanic water transport are few, including the mixing of fresh water through the oceanic boundary layer, transport by ocean currents, and sea ice processes. On land the situation is considerably more complex, and includes the deposition of rain and snow on land; water flow in runoff; infiltration of water into the soil and groundwater; storage of water in soil, lakes and streams, and groundwater; polar and glacial ice; and use of water in vegetation and human activities. Illustration of the water cycle showing the ocean, land, mountains, and rivers returning to the ocean. Processes labeled include: precipitation, condensation, evaporation, evaportranspiration (from tree into atmosphere), radiative exchange, surface runoff, ground water and stream flow, infiltration, percolation and soil moisture.