{"id":13233,"date":"2015-09-14T07:00:29","date_gmt":"2015-09-14T12:00:29","guid":{"rendered":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/short-reads\/%year%\/%monthnum%\/%day%\/does-waters-boiling-point-change-with-altitude-americans-arent-sure\/"},"modified":"2024-04-14T03:19:22","modified_gmt":"2024-04-14T08:19:22","slug":"does-waters-boiling-point-change-with-altitude-americans-arent-sure","status":"publish","type":"short-read","link":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/short-reads\/2015\/09\/14\/does-waters-boiling-point-change-with-altitude-americans-arent-sure\/","title":{"rendered":"Does water\u2019s boiling point change with altitude? Americans aren\u2019t sure"},"content":{"rendered":"

SPOILER ALERT: If you haven’t already done so, test yourself with our new Science Knowledge Quiz<\/a>. We discuss one of the answers to the questions below.<\/em><\/p>\n\n

\"elevation<\/a><\/figure>\n\n

It seems like one of those basic science facts: Water boils at 212 degrees Fahrenheit (100 degrees Celsius), right? Well, not always. It\u00a0depends on where you’re doing the boiling.<\/p>\n\n

In fact, water will boil at about 202 degrees in Denver, due to the lower air pressure at such high elevations. In Pew Research Center’s recent\u00a0survey on science knowledge<\/a>,\u00a0only 34% of Americans knew that water boils at a lower temperature in\u00a0the Mile High City\u00a0than in Los Angeles, which is close to sea level. This was the question in our quiz<\/a>\u00a0that the fewest people answered correctly: 26% said they thought water would boil at a higher<\/em> temperature in Denver, while 39% said it would boil at the same<\/em> temperature in both places.<\/p>\n\n

The boiling point of water, or\u00a0any liquid, varies according to the surrounding atmospheric\u00a0pressure.\u00a0A liquid boils, or begins turning to vapor,\u00a0when its internal vapor pressure equals the atmospheric\u00a0pressure. For instance, when you heat your tea kettle on a stovetop, you’re creating more water vapor; when the water’s vapor pressure rises enough to exceed the surrounding air pressure, bubbles start to form and the water boils.<\/p>\n\n

But pressure drops as you gain elevation<\/a> \u2013 say, by driving from Los Angeles\u00a0to Denver \u2013 because there are fewer air molecules pressing on you. In Denver, the atmospheric pressure is only about 12 pounds per square inch, compared with\u00a014.7 pounds per square inch in Los Angeles.\u00a0With that much less pressure, you don’t need to apply as much\u00a0heat to push vapor pressure beyond the surrounding atmospheric pressure \u2013 in other words, water boils at a lower temperature. Putting a liquid in a partial vacuum also will lower its boiling point. The reason is the same: By removing some of the air surrounding the liquid, you’re\u00a0lowering the atmospheric pressure on it.<\/p>\n\n

In La Rinconada, a mining town in the Peruvian Andes that, at more than 16,700 feet, is the highest permanently inhabited town in the world, water will boil at about 181 degrees. Were you of a mind to brew yourself a nice cup of tea at the peak of Mount Everest (29,029 feet), you’d only have to bring your water up to about 162 degrees for it to boil. At another extreme, in\u00a0Death Valley, Calif. \u2013\u00a0the\u00a0lowest point in the U.S.,\u00a0at\u00a0282 feet below sea level\u00a0\u2013\u00a0water boils at slightly\u00a0above<\/em> 212 degrees.<\/p>\n\n

The lower atmospheric pressures at high elevations\u00a0affect cooking and baking, too, which is why many recipes and mixes come with special “high altitude” directions. Cooking<\/a> generally takes longer at elevations above 3,000 feet or so, and foods tend to\u00a0dry out faster. Doughs will rise faster<\/a> (because gases expand more) and liquids in batters evaporate faster.<\/p>","protected":false},"excerpt":{"rendered":"

Only 34% of Americans correctly answered a question about the difference (if any) between boiling water in Los Angeles and Denver. So what’s the right answer, and why?<\/p>\n","protected":false},"author":145,"featured_media":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"sub_headline":null,"sub_title":"","_prc_public_revisions":[],"_ppp_expiration_hours":0,"_ppp_enabled":false,"ai_generated_summary":"","apple_news_api_created_at":"","apple_news_api_id":"","apple_news_api_modified_at":"","apple_news_api_revision":"","apple_news_api_share_url":"","apple_news_cover_media_provider":"image","apple_news_coverimage":0,"apple_news_coverimage_caption":"","apple_news_cover_video_id":0,"apple_news_cover_video_url":"","apple_news_cover_embedwebvideo_url":"","apple_news_is_hidden":"","apple_news_is_paid":"","apple_news_is_preview":"","apple_news_is_sponsored":"","apple_news_maturity_rating":"","apple_news_metadata":"\"\"","apple_news_pullquote":"","apple_news_pullquote_position":"","apple_news_slug":"","apple_news_sections":[],"apple_news_suppress_video_url":false,"apple_news_use_image_component":false,"relatedPosts":[],"_prc_fork_parent":0,"_prc_fork_status":"","_prc_active_fork":0,"datacite_doi":"","datacite_doi_citation":"","_prc_seo_qr_attachment_id":0,"spoken_article_player_enabled":true,"displayBylines":true,"footnotes":"","prc_watchers":[]},"categories":[364,262,258],"bylines":[842],"collection":[],"datasets":[],"_post_visibility":[],"formats":[467],"_fund_pool":[],"languages":[],"regions-countries":[515],"research-teams":[526,518],"workflow-status":[],"class_list":["post-13233","short-read","type-short-read","status-publish","hentry","category-public-knowledge","category-science-knowledge","category-stem-education-workforce","bylines-drew-desilver","formats-short-read","regions-countries-united-states","research-teams-internet","research-teams-science"],"label":"Short Read","post_parent":0,"word_count":479,"canonical_url":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/short-reads\/2015\/09\/14\/does-waters-boiling-point-change-with-altitude-americans-arent-sure\/","art_direction":{"A1":{"id":24437,"rawUrl":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-content\/uploads\/sites\/20\/2015\/09\/FT__15.09.11_boilingKettle-jpg.webp","url":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-content\/uploads\/sites\/20\/2015\/09\/FT__15.09.11_boilingKettle-jpg.webp?w=564&h=317&crop=1","width":564,"height":317,"chartArt":false},"A2":{"id":24437,"rawUrl":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-content\/uploads\/sites\/20\/2015\/09\/FT__15.09.11_boilingKettle-jpg.webp","url":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-content\/uploads\/sites\/20\/2015\/09\/FT__15.09.11_boilingKettle-jpg.webp?w=268&h=151&crop=1","width":268,"height":151,"chartArt":false},"A3":{"id":24437,"rawUrl":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-content\/uploads\/sites\/20\/2015\/09\/FT__15.09.11_boilingKettle-jpg.webp","url":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-content\/uploads\/sites\/20\/2015\/09\/FT__15.09.11_boilingKettle-jpg.webp?w=194&h=110&crop=1","width":194,"height":110,"chartArt":false},"A4":{"id":24437,"rawUrl":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-content\/uploads\/sites\/20\/2015\/09\/FT__15.09.11_boilingKettle-jpg.webp","url":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-content\/uploads\/sites\/20\/2015\/09\/FT__15.09.11_boilingKettle-jpg.webp?w=268&h=151&crop=1","width":268,"height":151,"chartArt":false},"XL":{"id":24437,"rawUrl":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-content\/uploads\/sites\/20\/2015\/09\/FT__15.09.11_boilingKettle-jpg.webp","url":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-content\/uploads\/sites\/20\/2015\/09\/FT__15.09.11_boilingKettle-jpg.webp?w=640&h=360&crop=1","width":640,"height":360,"chartArt":false},"social":{"id":24437,"rawUrl":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-content\/uploads\/sites\/20\/2015\/09\/FT__15.09.11_boilingKettle-jpg.webp","url":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-content\/uploads\/sites\/20\/2015\/09\/FT__15.09.11_boilingKettle-jpg.webp?w=640&h=360&crop=1","width":640,"height":360,"chartArt":false}},"_embeds":[],"watchers":[],"table_of_contents":[],"datacite_doi":"","prc_seo_data":{"title":"Does water\u2019s boiling point change with altitude? Americans aren\u2019t sure","description":"Only 34% of Americans answered correctly when asked the difference (if any) between boiling water in Los Angeles and Denver. So what's the answer, and why?","og_title":"Does water\u2019s boiling point change with altitude? Americans aren\u2019t sure","og_description":"Only 34% of Americans correctly answered a question about the difference (if any) between boiling water in Los Angeles and Denver. So what's the right answer, and why?","schema_type":"Article","noindex":false,"canonical_url":"","primary_terms":[],"custom_schema":[],"og_image":24437,"indexnow_submitted_at":null,"gsc_index_status":null},"prepublish_checks":{},"apple_news_notices":[],"jetpack_sharing_enabled":true,"relatedPostsOrdered":[],"bylinesOrdered":[{"key":"61502851-e3b9-430b-9fa4-f6e485799f33","termId":842}],"acknowledgementsOrdered":[],"_links":{"self":[{"href":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-json\/wp\/v2\/short-read\/13233","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-json\/wp\/v2\/short-read"}],"about":[{"href":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-json\/wp\/v2\/types\/short-read"}],"author":[{"embeddable":true,"href":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-json\/wp\/v2\/users\/145"}],"replies":[{"embeddable":true,"href":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-json\/wp\/v2\/comments?post=13233"}],"version-history":[{"count":2,"href":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-json\/wp\/v2\/short-read\/13233\/revisions"}],"predecessor-version":[{"id":103170,"href":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-json\/wp\/v2\/short-read\/13233\/revisions\/103170"}],"wp:attachment":[{"href":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-json\/wp\/v2\/media?parent=13233"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-json\/wp\/v2\/categories?post=13233"},{"taxonomy":"bylines","embeddable":true,"href":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-json\/wp\/v2\/bylines?post=13233"},{"taxonomy":"collection","embeddable":true,"href":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-json\/wp\/v2\/collection?post=13233"},{"taxonomy":"datasets","embeddable":true,"href":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-json\/wp\/v2\/datasets?post=13233"},{"taxonomy":"_post_visibility","embeddable":true,"href":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-json\/wp\/v2\/_post_visibility?post=13233"},{"taxonomy":"formats","embeddable":true,"href":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-json\/wp\/v2\/formats?post=13233"},{"taxonomy":"_fund_pool","embeddable":true,"href":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-json\/wp\/v2\/_fund_pool?post=13233"},{"taxonomy":"languages","embeddable":true,"href":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-json\/wp\/v2\/languages?post=13233"},{"taxonomy":"regions-countries","embeddable":true,"href":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-json\/wp\/v2\/regions-countries?post=13233"},{"taxonomy":"research-teams","embeddable":true,"href":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-json\/wp\/v2\/research-teams?post=13233"},{"taxonomy":"workflow-status","embeddable":true,"href":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/wp-json\/wp\/v2\/workflow-status?post=13233"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}